احياء السادس العلمي - الفصل الثالث (التكاثر) منهج متميزين/كلية بغداد/موهوبين

CHAPTER III -
REPRODUCTION
Yotube channel: RamadhanSci
Email: Ramadhansuhaib@gmail.com
Instagram Acc: Beanspopsicle

RamadhanSci 1
All organisms must produce new individuals similar to itself to preserve the species
★ Organisms don’t need reproduction to survive but they need it for continuity of their
generations.
Meaning, I can still live a normal life without having children, but if the entire human species
stops reproducing, it will ultimately lead to extinction.
Reproduction differs from other life activities like digestion, respiration, circulation, and
excretion, as these functions are essential for an organism’s survival. In contrast, reproduction is
not necessary for an individual’s survival—an organism may be unable to reproduce or lack fully
developed reproductive organs yet still maintain a healthy body and continue living.
Any organism without functional reproductive organs cannot continue its generation and will
eventually disappear.
Q/ Justify or Explain: Reproduction is NOT essential for the survival of an individual organism
OR
Q/ Justify or Explain: Reproduction is essential for the survival of the species but not the
individual organism.
OR
Q/ Justify or Explain: Reproduction is not essential for the survival of an individual but is
essential for the continuation of the species.
ANS: Read the above.
Q: Justify or Explain: Reproduction differs from other life activities like digestion, and
respiration.
ANS: Reproduction differs from other life activities like digestion, respiration, circulation, and
Q: _________ differs from other life activities like digestion, respiration, circulation, and
excretion in that it is not essential for the individual's survival.
ANS: Reproduction.
______ means production of new individuals approximately similar to parent. → Reproduction.
Q/ Give an example for each of the following:
1. Organism reproduce by means of asexual reproduction
2. Organism reproduce by means of sexual reproduction
ANS:
1. Primitive organisms (unicellular prokaryotes), e.g. Bacteria.
2. Most multicellular eukaryotes, like animals (including humans), and plants.

RamadhanSci 2
★ Sexual reproduction is more complicated process than asexual reproduction. But both types
of reproduction have two main states (or principles, or aspects):
1. The collection of pure substances from the environment and their transmission to the
next generation.
2. The transmission of genetic material (DNA) to the next generation.
Q/ What are the main principles (or aspects, or states) of both sexual and asexual reproduction?
ANS: The two states above.
In certain animal populations, reproduction is carried out by only a small number of individuals.
For example, in a beehive, most bees are sterile female workers with no role in reproduction.
The drones (male bees) are capable of reproduction but are fewer in number, while only one
female, the queen, is responsible for reproduction.
Q/ Give an example for each of the following: an animal population where only a small number
of individuals are involved in reproduction?
ANS: Bees.
Q/ There are two main types of reproduction: _______ reproduction and _______
reproduction? ➔ asexual, sexual.
Asexual reproduction: Some organisms can generate new individuals by breaking off a part of
their body, which then develops into an independent organism. This type of reproduction can
result in the formation of one or more new organisms.
Sexual reproduction: Most plants and a large number of animals are characterized by having
distinct male and female members. Males produce sperm, while females produce eggs (ova).
These organisms differ in their anatomy, physical characteristics, and the structure of their
reproductive organs.
Sexual reproduction occurs through the union of male and female reproductive cells in a
process called fertilization.
Q/ Sexual reproduction passes through two main steps, explain them.
ANS:
1. In the first step, the cell undergoes meiosis, reducing the chromosome number so that
the resulting cells receive half of the original chromosomes.
2. In the second step, two gametes unite in a process called fertilization, forming a zygote
with the full chromosome number (2n). This zygote then grows into a new organism
through a series of mitotic divisions.

RamadhanSci 3
Q/ Compare: Sexual and Asexual reproduction
ANS:
Sexual reproduction Asexual reproduction
Occurs in animals and plants. Occurs in less developed and unicellular
organisms.
Happens through the union of male and
female reproductive cells in a process called
fertilization.
Happen when an organism generates a new
individual by breaking off a part of their body,
which then develops into an independent
organism.
The new organism formed have traits from
both parents.
The new organism formed have identical
traits from the parent cell.
Complex process Simple process
Example: Reproduction in humans Example: Binary fission in bacteria

RamadhanSci 4
Spermatogenesis:
+ period of growth
Each spermatid undergoes changes in
shape and structure (spermiogenesis)
n

RamadhanSci 5
Q/ Draw with labeling: Stages of sperm formation
Or
Q/ Draw with labelling: Spermatogenesis
Or
Q/ Draw with labelling: Spermatogenesis in mammals (this is how it's written in the Arabic
version of the book, so it's likely to appear this way)
ANS:
★ Sperms are formed in the testes which consist of a large number of seminiferous tubules.
Q/ What is the location and function of seminiferous tubules?
ANS:
Location: In the testes.
Function: The lining of the seminiferous tubules contain the germ cells (thus they produce
sperm).

RamadhanSci 6
Sperms are formed in the testes, which consist of a large number of seminiferous tubules. These
tubules are lined with primitive germ cells that undergo multiple successive mitotic divisions,
producing new cells called spermatogonia, and they are diploid (2n). Spermatogonia then
continue to divide by mitosis, increasing their numbers through duplication.
Each spermatogonium passes through a growth phase after division stops, increasing in size and
forming a primary spermatocyte.
Each primary spermatocyte undergoes the first meiotic division, producing two equal-sized
haploid (n) cells called secondary spermatocytes.
Secondary spermatocytes undergo the second meiotic division, resulting in four equal-sized
haploid (n) cells called spermatids.
Each spermatid undergoes structural and morphological changes to form a mature sperm cell.
Attention: The final result of spermatogenesis is four mature sperm cells.

RamadhanSci 7
Oogenesis:
Germ cell
↓
Mitotic divisions
↓
Mitotic division + Passes through a
period of growth to increase in volume
Ooblast
(n)

RamadhanSci 8
Q/ Draw with labeling: Stages of egg formation
Or
Q/ Draw with labelling: Oogenesis
Or
Q/ Draw with labelling: Oogenesis in mammals (this is how it's written in the Arabic version of
the book, so it's likely to appear this way)
ANS:

RamadhanSci 9
Ova are formed in the ovaries. Germ cells in the ovaries undergo mitotic divisions,
producing clusters of cells called oogonia.
Oogonia undergo further successive mitotic divisions, producing additional oogonia, all
of which are diploid (2n).
A portion of these cells begins to grow and increase in size, becoming known as primary
oocytes.
Primary oocytes are diploid (2n). In many animals, especially vertebrates, they are
surrounded by small cells called follicle cells. Together, the primary oocyte and its
surrounding follicle cells form a structure known as the ovarian follicle.
★ Ovarian follicle = Primary oocyte + follicle cells.
The primary oocyte undergoes first meiosis resulting in 2 cells not equal in size due to
the cytoplasmic division being unequal, and both cells are haploid (n).
The larger cell is called the secondary oocyte, and the smaller cell is called the first polar
body.
Q: Justify: The first meiotic division of the primary oocyte produces unequal-sized cells.
ANS: Because the cytoplasmic division is unequal. The larger cell produced is called
secondary oocyte, and the smaller cell is called first polar body.
The secondary oocyte undergoes the second meiosis, resulting in two unequal-sized
cells: the larger one called the ooblast, which grows to form the mature ovum, and the
smaller one called the second polar body. Both cells are haploid (n).
The first polar body may also divide, forming two polar bodies (secondary polar bodies).
The final result of this process (the oogenesis) is one mature ovum and three polar
bodies. The polar bodies eventually degenerate.
Q: What is the fate of polar bodies?
Or
Q: What is the fate of polar bodies formed in oogenesis?
ANS: They degenerate.

RamadhanSci 10
NOTE1: The English version of the book states that the type of division in the first polar
body is meiosis II.
Therefore, if a question asks about the type of division in the first polar body → Meiosis
II.
NOTE2: We said that the first polar body may divide, meaning it does not always divide
and sometimes simply degenerates.
Generally, if asked about the final result of oogenesis, the answer is one mature egg and
three polar bodies.
However, if they want to be creative, they might ask:
“In oogenesis, if the first polar body does not undergo further division and degenerates,
what will be the final result?”
The answer would be one mature egg and one polar body (the second polar body).
Q: What is the fate of the first polar body in oogenesis.
ANS: The first polar body may also divide (meiosis II), forming two polar bodies
(secondary polar bodies), but it does not always divide and sometimes simply
degenerates.
In the first scenario, the final result of oogenesis → one mature egg and three polar
bodies.
In the second scenario, the final result of oogenesis → one mature egg and one polar
body.

RamadhanSci 11
★ Reproductive cells (germ cells) in females are formed in the ovary.
★ Many small cells surround the primary oocyte, forming a layer known as follicle cells.
Together, the primary oocyte and these surrounding follicle cells make up the ovarian follicle.
Q/ Final result of oogenesis is _________? → one mature egg (ovum) and three polar bodies.
Q/ The result of Meiosis II of secondary oocyte is _______ and ______? → Ooblast and
secondary polar body.

RamadhanSci 12
Q/ What are the chromosome sets for each of the following:
Spermatogonium (pl.: spermatogonia) → 2n
Primary spermatocyte ➔ 2n
Oogonium (pl. Oogonia) → 2n
Primary oocyte ➔ 2n
Secondary spermatocyte ➔ n
Secondary oocyte ➔ n
Spermatid ➔ n
Ooblast ➔ n
Sperm cell (mature sperm) ➔ n
Ovum (egg) OR Mature ovum ➔ n
Primary polar body (1st
polar body) ➔ n
Secondary polar bodies (2nd
polar body) ➔ n
Germ cell ➔ 2n
Germ cells in male → 2n
Germ cells in females → 2n
Primitive germ cell → 2n
More Qs about spermatogenesis and oogenesis:
They might ask you a question like:
“What are the cellular changes that the primary spermatocyte undergoes until the formation
of a mature sperm? )‫”(وزاري‬
In this case, you should write down everything that happens from the primary spermatocyte
stage all the way to mature sperm formation.
Also, we can now predict that they might ask about any two stages they choose. For example,
one question could ask you to explain the entire process of spermatogenesis and oogenesis,
while another might ask you to describe the stages from the germ cell to the primary oocyte,
and so on.
Q: List the stages of spermatogenesis and indicate (or specify) the chromosome set for each
stage. )‫(وزاري‬
ANS:
Stage Chromosome set
Primitive germ cell 2n
Spermatogonia 2n
Primary spermatocyte 2n
Secondary spermatocyte n
Spermatid n

RamadhanSci 13
Mature sperm n
Q: List the stages of oogenesis and indicate (or specify) the chromosome set for each stage.
)‫(وزاري‬
ANS:
Stage Chromosome set
Germ cell 2n
Oogonia 2n
Primary oocyte 2n
Secondary oocyte + First polar body n
Ooblast + Second polar body n
Mature ovum n
Q: What is the origin of (or who is responsible for):
1- Second polar body
2- Secondary oocyte
ANS:
1- From Meiosis II of secondary oocyte OR From Meiosis II of first polar body.
2- From Meiosis I of primary oocyte.
1- Spermatogonia
2- Oogonia
ANS:
1- From the primitive germ cells lining the seminiferous tubules in the testes.
2- From the germ cells in the ovaries.
1- Primary oocyte
2- Secondary oocyte
3- Primary spermatocyte
4- Secondary spermatocyte
5- Spermatid
6- Ooblast
7- Mature sperm
8- Mature ovum

RamadhanSci 14
ANS:
1- From oogonia growth and increase in size.
2- Meiosis I of primary oocyte
3- From spermatogonia growth and increase in size.
4- From Meiosis I of primary spermatocyte
5- From Meiosis II of secondary spermatocyte
6- Meiosis II of secondary oocyte
7- Growth and structural and morphological changes of spermatids in spermatogenesis
(more specifically spermiogenesis)
8- Growth of ooblast
1- First polar body
2- Second polar body
ANS:
1- Meiosis I of primary oocyte.
2- Meiosis II of secondary oocyte OR From Meiosis II of first polar body.
Q: What is the origin of (or who is responsible for): All three second polar bodies.
ANS: Meiosis II of secondary oocyte (gives one second polar body) AND Meiosis II of first polar
body (gives two second polar bodies).
Q: Sperms are formed in the _________, which consist of a large number of __________.
)‫(وزاري‬
ANS: Testes; Seminiferous tubules.
Q: Define: Ovarian follicle
ANS: is the structure formed by the primary oocyte and its surrounding follicle cells. This feature
is found in many animals especially vertebrates.
Q: Define Follicle cells
ANS: Are cells surrounding the primary oocyte to from a structure called ovarian follicle. This
feature is found in many animals, especially vertebrates.
Q: Give an example for each: species or organisms possessing the structure “ovarian follicle”
ANS: Many animals, especially vertebrates.
Q: Give an example for each: species or organisms having follicle cells around the primary
oocyte.
ANS: Many animals, especially vertebrates.

RamadhanSci 15
Q: What is the location and function of germ cells in male?
ANS:
Location → Lining the seminiferous tubules in the testes.
Function → Undergo multiple successive mitotic divisions, producing new cells called
spermatogonia.
Q: What is the location and function of germ cells in female?
ANS:
Location → in ovaries.
Function → Undergo mitotic divisions, producing clusters of cells called oogonia.
Q: Justify or Explain: During gametogenesis, male gametes vastly outnumber female gametes.
ANS:
This is because, in oogenesis, the cytoplasmic divisions are unequal, resulting in one large
oocyte and small polar bodies that eventually degenerate. In contrast, spermatogenesis involves
equal cytoplasmic divisions, producing four viable sperm cells from each primary spermatocyte.

RamadhanSci 16
Reproduction in viruses:
Q: Define viruses
Or
Q: What are the characteristics (or features) of viruses )‫(وزاري‬
ANS:
Viruses are tiny structures that can only be seen with an electron microscope. They represent a
link between living organisms and non-living matter. Viruses cause diseases in humans, animals,
and plants.
Viruses are able to grow and reproduce only inside the living cells of other organisms, but they
cannot survive in the external environment. This is because they lack the cellular machinery
required for independent life. Specifically, viruses do not possess cellular organelles, including
enzyme systems necessary for respiration, protein synthesis, and the duplication of nucleic
acids.
Q: Justify or Explain: Viruses represent a link between living organisms and non-living matter.
)‫(وزاري‬
ANS: Because viruses are able to grow and reproduce only inside the living cells of other
organisms, but they cannot survive in the external environment.
Q: Justify or Explain: Viruses cannot survive outside of the cells (or in the external
environment) )‫(وزاري‬
Or
Q: Justify or Explain: Viruses cannot have an independent life )‫(وزاري‬
ANS: Because viruses do not possess cellular organelles, including enzyme systems necessary
for respiration, protein synthesis, and the duplication of nucleic acids.
Information about viral reproduction has been obtained by observing a type of virus that attacks
a bacterium called Escherichia coli. These viruses, which infect bacteria, are known as
bacteriophages. Viruses can reproduce through two interconnected cycles: the lytic cycle and
the lysogenic cycle.
Q: The viruses that attack E. Coli are called ________.
ANS: Bacteriophages.
Q: The viruses that attack the bacterium _________ are called bacteriophages.
ANS: Escherichia coli.
Q: List only: The cycles of virus reproduction (without the stages)
ANS:
1- Lytic cycle
2- Lysogenic cycle

RamadhanSci 17
Q: Viruses can reproduce through two interconnected cycles: ____________ and
____________. )‫(وزاري‬
ANS: The lytic cycle; The lysogenic cycle.
Lytic cycle:
Q/ List only: The stages of lytic cycle. (important Q)
ANS:
1- Attachment stage
2- Penetration stage
3- Biosynthesis stage
4- Maturation stage
5- Release stage
1- Attachment stage (Q/ Explain [or write down what you know about] the attachment stage
of virus reproduction OR Q/ Define the attachment stage [of virus reproduction]):
At this stage, the virus approaches the bacterial cell. When it comes into contact with the
bacterium, the fibers in its tail stick to special positions on the wall of the host cell.
Q: Give an example for each of the following: A host cell.
ANS: Bacterial cell.
Q: Give an example for each of the following: A host cell targeted by a virus.
ANS: A bacterial cell (e.g., by a bacteriophage).
Q: When the virus comes into contact with the bacterium, the ______ in its tail stick to special
positions on the _____________. )‫(وزاري‬
ANS: Fibers; Wall of the host cell.
Q: What is location for each of the following: Viral fibers that attach to the bacterial cell wall.
ANS: In the tail.
2- Penetration stage (Q/ Explain [or write down what you know about] the penetration stage
of virus reproduction OR Q/ Define the penetration stage [of virus reproduction]):
The enzyme found in the tail of the virus can weaken the chemical bonds in the bacterial cell
wall (decomposes the cell wall) at the site of attachment. This leads to the formation of a small
pore through which the viral DNA (or nucleic acids) enter the host cell.
Q: Justify or Explain: The tail of the virus secretes an enzyme when attached to the bacterial
cell. )‫(وزاري‬

RamadhanSci 18
ANS: Because this enzyme can weaken the chemical bonds in the bacterial cell wall
(decomposes the cell wall) at the site of attachment. This leads to the formation of a small
pore through which the viral DNA (or nucleic acids) enter the host cell.
Q: What is location for each of the following: Weakened chemical bonds of bacterial cell wall
due to the enzyme secreted by the virus tail.
ANS: At the site of attachment.
Q: Who is responsible for each of the following:
1- weakened chemical bonds in the host cell wall.
2- Injection of viral DNA into the host cell.
ANS:
1- The enzyme found in the tail of the virus
2- The small pore formed due to the weakening of the chemical bonds of the cell wall by the
viral tail enzyme.
3- Biosynthesis stage (Q/ Explain [or write down what you know about] the biosynthesis stage
of virus reproduction OR Q/ Define the biosynthesis stage [of virus reproduction]):
When viral DNA enters the bacterium, it transcribes viral mRNA needed for the production of
enzymes that degrade the bacterial DNA and mRNA. Then, the bacterial cellular machinery that
produces proteins and releases energy becomes under the control of the viral DNA.
Viral DNA directs the host's cellular machinery to produce new viral nucleic acids (DNA) and
viral proteins.
Q: Justify or Explain: When viral DNA enters the bacterium, the bacterial cellular machinery
that produces proteins and releases energy becomes under the control of the viral DNA.
)‫(وزاري‬
ANS: Because when viral DNA enters the bacterium, it transcribes viral mRNA needed for the
production of enzymes that degrade the bacterial DNA and mRNA. Then, the bacterial cellular
machinery that produces proteins and releases energy becomes under the control of the viral
DNA.
Q: Who is responsible for each of the following:
1- Transcription of viral mRNA.
2- Degradation of bacterial DNA and mRNA
3- Direction of bacterial cell to produce new viral nucleic acids and viral proteins
ANS:
1- Viral DNA
2- Enzymes produced with the help of viral mRNA which is transcribed by the viral DNA.
3- Viral DNA

RamadhanSci 19
4- Maturation stage (Q/ Explain [or write down what you know about] the maturation stage
of virus reproduction OR Q/ Define the maturation stage [of virus reproduction]):
Molecules of protein are organized in order to form protein covers around new strips of the viral
nucleic acid; as a result, 100–200 new viruses are made.
Q: What do the following sentences indicates:
- 100–200 new viruses are made.
ANS:
Maturation stage of virus reproduction. Molecules of protein are organized in order to form
protein covers around new strips of the viral nucleic acid; as a result, 100–200 new viruses are
made.
5- Release stage (Q/ Explain [or write down what you know about] the release stage of virus
reproduction OR Q/ Define the release stage [of virus reproduction]):
New viruses cause the decomposition of the host bacterial cell. These viruses are then released
to infect other uninfected bacteria. This entire process takes about 25 minutes. Over time,
viruses can destroy large clusters of bacteria.
NOTE: I am about 99.9% sure that the 25 minutes refers to the entire lytic cycle, not just the
release stage. However, there is a small chance (0.1%) that it could mean the release stage
alone, as the book isn’t entirely clear about the timeframe.
Either way, if you get a question about the duration, the best answer is 25 minutes, since that
is the only timeframe provided.
Lysogenic cycle:
Q/ List only: the stages of lysogenic cycle. (Possible Q)
ANS:
1- Attachment stage (just like in lytic cycle)
2- Penetration stage (just like in lytic cycle)
3- And in the Arabic version, the book quotes "
‫التكامل‬ ‫مرحلة‬
" which I would translate to
“integration stage” referring to the integration of viral DNA into the bacterial DNA, or
“completing stage” as it appears in the diagram.
In the lysogenic cycle, the attachment and penetration stages occur just like in the lytic cycle.
Then, the viral nucleic acid (DNA) integrates into the bacterial DNA without breaking it
(integration stage). This integrated viral DNA is called a prophage. The prophage is duplicated
when the bacterial cell reproduces.
Q: Which stages of viral reproduction are common to both the lytic and lysogenic cycles?

RamadhanSci 20
ANS:
- Attachment stage
- Penetration stage
Q: Which stage of viral reproduction in unique to the lysogenic cycle?
ANS: integration stage.
Q: Which stages of viral reproduction are unique to the lytic cycle only (i.e., does NOT happen in
the lysogenic cycle)?
ANS:
- Biosynthesis stage
- Maturation stage
- Release stage
Q: Define: Lysogenic cycle )‫(وزاري‬
ANS: In the lysogenic cycle, the attachment and penetration stages occur just like in the lytic
cycle. Then, the viral nucleic acid (DNA) integrates into the bacterial DNA without breaking it
(integration stage). This integrated viral DNA is called a prophage. The prophage is duplicated
when the bacterial cell reproduces.
Q: The viral DNA integrated into bacterial DNA is called ________.
ANS: Prophage.
Q: Who is responsible for each of the following: Prophage duplication
ANS: Bacterial cell reproduction.
Q: Define: Prophage (important Q)
ANS: Is the viral DNA integrated into the bacterial DNA without breaking it (integration stage),
following the attachment and penetration stages of lysogenic cycle. This prophage is
duplicated when the bacterial cell reproduces.

RamadhanSci 21
Q: Draw with labelling: Reproduction in viruses
ANS:
Bacterial cell

RamadhanSci 22
Reproduction in Monera:
Monera includes bacteria and cyanobacteria (Blank Questions). It reproduces both sexually and
asexually. In this lesson, we will focus on bacterial reproduction as an example of reproduction
in Monera.
Q: Monera reproduces both _______ and _________.
ANS: Sexually; Asexually.
Q: Bacteria reproduces both _______ and _________.
Q: Cyanobacteria reproduces both _______ and _________.
Q: Mention the reproduction type in:
1- Monera
2- Bacteria
3- Cyanobacteria
ANS: Sexual and Asexual.
Asexual reproduction in bacteria:
Bacteria reproduce asexually by binary fission.
Q: Bacterial reproduce asexually by _______.
ANS: Binary fission.
Q: What is the type of asexual reproduction in bacteria? )‫(وزاري‬
ANS: Binary fission.
Again, Bacteria reproduce asexually by binary fission.
This can be summarized as follows (Q/ Explain the asexual reproduction in bacteria OR Q/
Write down what you know about asexual reproduction in bacteria):
- The bacterial chromosome attaches to the plasma membrane at a specific site,
indicating that the cell is ready for division.

RamadhanSci 23
- The bacterial cell prepares for binary fission by expanding its cell wall and plasma
membrane, causing the entire cell to enlarge.
- The division of DNA produces two identical chromosomes, and at the same time, the cell
wall and plasma membrane begin to pinch inward.
- As a result of this stretching, the two chromosomes move in opposite directions within
the cell. At the same time, the cytoplasm spreads, and the overall cell elongation
increases.
- The cell divides, producing two identical daughter cells.
Q: Draw with labelling: Asexual reproduction in bacteria (binary fission)
ANS:

RamadhanSci 24
Sexual reproduction in bacteria:
Bacteria reproduce sexually through conjugation, which occurs between different strains of
the same bacterial species.
★ “different strains of the same bacterial species“ What does that mean?
→ "Species": A group of bacteria that are very similar, for example, E. coli is a species.
"Strains": Variants within that species, they are still E. coli, but they may have small genetic
differences (like resistance to antibiotics, or ability to produce toxins).
Example: E. coli strain A has antibiotic resistance, and E. coli strain B does not ➔ Through
conjugation, strain A can transfer that resistance gene to strain B.
Q: What is the type of sexual reproduction in bacteria? (important Q)
ANS: Conjugation.
Q: Bacteria reproduce sexually through _________.
ANS: Conjugation.
Again, bacteria reproduce sexually through conjugation, which occurs between different strains
of the same bacterial species. Scientists found that when two different strains of colon bacteria
(E. coli) are mixed in the same culture medium, a new strain appears with functions that differ
from the two original strains. This indicates that a type of genetic exchange occurs between the
two cells, a process known as recombination.
Q: Define: Recombination
ANS: A type of genetic exchange that occurs when two different strains of colon bacteria (E.
coli) are mixed in the same culture medium, resulting in the formation of new strain with
functions that differ from the two original strains.
Q: What is location (or, where does it occur) and function (or importance) of recombination?
ANS:
Location → Two different strains of colon bacteria (E. coli) when mixed in the same culture
medium.
Importance → Results in the formation of a new strain with functions that differ from the two
original strains that were mixed.

RamadhanSci 25
Q: Justify or Explain: New strain of E. coli is formed when two strains are mixed in the same
culture medium. )‫(وزاري‬
ANS: Because a type of genetic exchange occurred between the two cells, a process known as
recombination.
Conjugation within bacteria occurs through the following steps (Q/ Explain conjugation in
bacteria OR Q/ Write down what you know about conjugation in bacteria):
- Conjugation occurs between two bacterial cells. The first cell is called the donor cell. It
contains the fertility factor (F factor), which is represented by DNA particles in its
cytoplasm. Donor cells also have sex pili on their surface, which qualifies them as male
cells. The second cell is the recipient cell, which lacks both the fertility factor and sex
pili, and is referred to as the female cell.
- When the sex pilus touches the surface of the recipient cell, it transforms into a
conjugation bridge that connects the protoplasm of the two bacterial cells.
- The fertility factor integrates into the donor cell’s chromosome and becomes a part of it.
- One of the strands of the donor’s chromosome breaks at a specific location and begins
to move through the conjugation bridge, transferring part of the donor’s chromosome
into the recipient cell. The donor cell does not lose genetic material because the broken
strand is regenerated. In the recipient cell, the transferred chromosome segment does
not add to the existing chromosome but instead replaces an equivalent portion of it.
This type of genetic reproduction is considered non-standard (not ordinary) because the
new bacterial cell does not receive a full set of genes from both original cells.
Conjugation can also occur in bacteria when the plasmid or fertility factor (a small circular DNA
molecule) is transferred from a donor cell to a recipient cell that lacks the plasmid. The transfer
takes place through the conjugation bridge between the two cells, and by the end of the
process, both cells will possess the F factor.
Q: What is the chromosome set in bacteria? )‫(وزاري‬
ANS: n.
Q: What is the chromosome set in: )‫(وزاري‬
1- Donor cell
2- Recipient cell
ANS:
1- n.
2- n.
Q: Define: Fertility factor )‫(وزاري‬

RamadhanSci 26
Or
Q: Define: Plasmid )‫(وزاري‬
ANS: is a small circular DNA molecule found in the cytoplasm of the donor cell and is NOT
found in the recipient cell. The fertility factor integrates into the donor cell’s chromosome and
becomes a part of it in order to transfer part of the donor’s chromosome into the recipient
cell through the conjugation bridge.
Q: What is location and importance (function) of plasmid (or fertility factor) )‫(وزاري‬
ANS:
Location → The cytoplasm of the donor cell.
Function → integrates into the donor cell’s chromosome and becomes a part of it in order to
transfer part of the donor’s chromosome into the recipient cell through the conjugation
bridge.
Q: What is the chemical composition of plasmid?
ANS: Small circular DNA molecule.
Q: Justify or Explain: The sexual reproduction in bacteria is considered non-standard (not
ordinary). )‫(وزاري‬
ANS: Because the new bacterial cell does not receive a full set of genes from both original
cells.
Q: Justify or Explain: The transferred chromosome segment in the recipient cell does not add
to the existing chromosome. )‫(وزاري‬
ANS: Because it replaces an equivalent portion of it.
Q: Justify or Explain: The donor cell does not lose genetic material.
ANS: Because the broken strand is regenerated in the donor cell.
Q: Conjugation in bacteria between two cells: ________ and ________. )‫(وزاري‬
ANS: Donor cell; Recipient cell.
Q: What is the location of conjugation bridge? )‫(وزاري‬
ANS: Between the two cells (donor and recipient) in conjugation.

RamadhanSci 27
Q: Who is responsible for each of the following: Conjugation bridge. )‫(وزاري‬
ANS: When the sex pili on the donor cell’s surface connect to the recipient cell.
Q: What are the characteristics (or features) of donor cell? )‫(وزاري‬
ANS:
1- Contains fertility factor
2- Contains sex pili on their surface
3- It qualifies as a male cell.
4- Haploid cells (n) - OR you can write it down as “single set of chromosomes,” or “one set of
chromosomes,” in fact, it doesn’t matter how you write it.
5- Part of its chromosome is transferred to the recipient cell during conjugation.
Q: What are the characteristics (or features) of recipient cell? )‫ومهم‬ ‫(مشابه‬
ANS:
1- Does NOT contain fertility factor
2- Does not contain sex pili
3- It qualifies as a female cell
4- Haploid cells (n).
5- It receives part of the donor cell's chromosome during conjugation.
Q: Draw with labelling: conjugation in bacteria (E. coli or colon bacteria)
ANS:

RamadhanSci 28
Reproduction in Protista:
Protista includes various types of unicellular organisms. We will study the reproduction of
Chlamydomonas, Euglena, and Paramecium as examples.
Q: Give an example of an organism that belongs to Protista.
ANS: Paramecium, Euglena, Chlamydomonas.
Reproduction in Chlamydomonas:
Q/ Define: Chlamydomonas
Or
Q/ What are the characteristics (or features) of Chlamydomonas?
ANS:
Chlamydomonas is a unicellular organism from the green algae group. It lives in lakes,
reservoirs, ponds, and swamps. Its green cell is characterized by having two flagella. It is
surrounded by a thick cellulose wall and contains a single green plastid with a cup-like shape.
Chlamydomonas reproduces both sexually and asexually.
Q: A distinguishing feature of Chlamydomonas is the presence of ________.
ANS: Two flagella.
Q: The Chlamydomonas is surrounded by __________ and contains a _______ with a ______
shape.
ANS: Thick cellulose wall; Single green plastid; Cup-like.
Q: Describe the flagella in Chlamydomonas
ANS: They’re two flagella (a pair).
Q: What do the following sentences indicate: a single green plastid with cup-like shape.
ANS: The green plastid in Chlamydomonas.
Asexual reproduction in Chlamydomonas (Q/ Explain [or write down what you know about]
the Asexual reproduction in Chlamydomonas ‫جدا‬ ‫ومهم‬ ‫متكرر‬ ‫)وزاري‬:
Asexual reproduction begins with the formation of 2 to 8, or even 16 motile zoospores, which
are capable of moving and swimming in water. Cell division occurs inside the original cell, within

RamadhanSci 29
its cellulose wall. The spores (i.e., the zoospores) are released when the cellulose wall of the
mother cell breaks down. Each zoospore then grows into an independent vegetative cell that
can swim in water.
Note: The word “zoospore” means ➔ a motile spore capable of moving or swimming, usually
by means of one or more flagella. Zoospores are produced by certain algae, fungi, and
protozoans during asexual reproduction to help disperse and colonize new environments.
★ The vegetative cells are the non-reproductive Chlamydomonas cell, and they are haploid
(n).
Q: What are the chromosomes sets for each of the following:
1- Vegetative cells of Chlamydomonas )‫(وزاري‬
2- Zoospore in Chlamydomonas (or if they wanted to be extra annoying, they would say
“spores in Chlamydomonas”)
ANS:
1- Haploid (n).
2- Haploid (n).
Q: What is the type of asexual reproduction in Chlamydomonas? )‫(وزاري‬
ANS: Formation of motile zoospores (swimming zoospores).
Q: Give an example for each of the following: A motile spore that can swim in water.
ANS: Zoospore (zoospores in general but you can add “in Chlamydomonas”).
Q: Give an example of an organism reproduces by the formation of motile zoospores, and what
is the type of reproduction (i.e., sexual or asexual)?
ANS: Chlamydomonas. Type of reproduction: Asexual.
Q: What do the following sentences indicate: Formation of 2 to 8, or even 16 motile
zoospores.
ANS: The beginning of asexual reproduction in Chlamydomonas.
Q: What is the location for each of the following: Cell division during asexual reproduction in
Chlamydomonas.
ANS: Inside the original cell, within its cellulose wall.

RamadhanSci 30
Q: What is the origin of (or who is responsible for) each of the following:
1- Release of spores in Chlamydomonas
2- Vegetative cell in Chlamydomonas
ANS:
1- The breakdown of the cellulose wall of the mother cell.
2- A zoospore grows into a new vegetative cell.
Sexual reproduction of Chlamydomonas (Q/ Explain [or write down what you know about]
the Sexual reproduction in Chlamydomonas ‫)وزاري‬:
Sexual reproduction in Chlamydomonas usually happens when the living conditions are poor
(unfavorable), and proceeds as follows:
- Chlamydomonas, which has a haploid number of chromosomes, undergoes a series of
normal divisions (i.e., mitosis). This results in the formation of 16 to 32 individuals within
the cellulose wall. These individuals are similar to the mother Chlamydomonas, but they
are much smaller and are called isogametes.
- The cell wall of the mother cell breaks down, releasing the isogametes into the water.
These isogametes then unite with other isogametes from a different strain, which were
formed in the same way.
- A zygote is formed as a result of the union of isogametes. This zygote is diploid (2n) and
initially has four flagella, making it a quadriflagellate structure. It swims in water for a
while, then loses its flagella. It becomes surrounded by a thick cellulose wall to resist
unfavorable environmental conditions and is then called a zygospore.
- When conditions become suitable, the zygospore reactivates and divides by meiosis to
produce four haploid (n) zoospores.
- The surrounding wall splits, releasing the four new zoospores, which are similar to the
mother cell. Each zoospore then grows and behaves as an independent mature
organism.
1- Chlamydomonas
2- Zygospore )‫(وزاري‬
3- Isogametes
4- Zygote )‫(وزاري‬
ANS:
1- Haploid (n).
2- Diploid (2n).
3- Haploid (n).
4- Diploid (2n).

RamadhanSci 31
Note: If the question simply asks about the “zygote,” then “diploid (2n)” is the most suitable
answer for most organisms. However, if the question specifically asks about the “zygote in
Chlamydomonas,” the answer remains diploid (2n).
Q: Justify or Explain: Chlamydomonas is haploid (n). )‫(وزاري‬
ANS: Because Chlamydomonas is produced by meiosis, it is haploid (n); thus, it has half the
number of chromosomes.
Q: Justify or Explain: Zygospore undergoes meiosis )‫(وزاري‬
ANS: To produce four haploid (n) zoospores.
Q: Define: Zygospore )‫(وزاري‬
ANS: is the zygote formed by the union of isogametes and is diploid (2n). It loses its four
flagella and becomes surrounded by a thick cellulose wall to resist unfavorable environmental
conditions.
Q: When does the following events occur: Sexual reproduction in Chlamydomonas.
ANS: When the living conditions are poor (unfavorable).
Q: Justify or Explain: Chlamydomonas may resort to sexual reproduction.
ANS: Sexual reproduction in Chlamydomonas usually happens when the living conditions are
poor (unfavorable).
Q: The new 16 to 32 Chlamydomonas individuals within the cellulose wall are referred to
________.
ANS: Isogametes.
★ Chlamydomonas → Mitosis → 16 to 32 new Chlamydomonas within the cellulose wall →
Similar to the mother Chlamydomonas, but they are much smaller and are called isogametes.
★ New 16 to 32 individuals within the cellulose wall = Isogametes.
Q: What is the initial location of the 16 to 32 new Chlamydomonas individuals formed by
mitosis?
Or

RamadhanSci 32
Q: What is the initial location of the new isogametes formed by mitosis?
ANS: Within the cellulose wall of the original (mother) cell.
Q: What is responsible for the formation of the 16 to 32 new Chlamydomonas individuals within
the cellulose wall?
Or
Q: What is responsible for the formation of new isogametes within the cellulose wall?
ANS: Mitosis in the haploid mother cell is responsible for their formation.
Q: What are the characteristics of the new 16 to 32 Chlamydomonas individuals formed by
mitosis?
Or
Q: What are the characteristics of isogametes?
ANS: They are initially located within the cellulose wall. They are similar to the mother
Chlamydomonas, but they are much smaller. Isogametes release into the water and unite
with other isogametes to form the zygote (2n). They are haploid (n) and motile (they possess
flagella).
Q: What is responsible for: Releasing isogametes into the water?
ANS: Break down of the cell wall of the mother cell.
Q: What is responsible for the formation of the zygote in Chlamydomonas?
ANS: Union of isogametes in the water.
Q: What is responsible for the formation of the zygospore in Chlamydomonas?
ANS: Union of isogametes + Loss of the four flagella + The surrounding cellulose wall.
Q: Give an example for each of the following: Quadriflagellate zygote.
Or
Q: Give an example for each of the following: A zygote with four flagella.
ANS: Chlamydomonas zygote.
Q: What are the characteristics (or features) of the zygote in Chlamydomonas?
ANS:
- Formed by the union of two isogametes

RamadhanSci 33
- Diploid (2n)
- Possesses four flagella (Quadriflagellate)
- Motile and can swim in water
- Is NOT surrounded by thick cellulose wall, thus, cannot resist unfavorable conditions.
Q: What are the characteristics (or features) of the zygospore?
ANS:
- Formed by the union of two isogametes
- Diploid (2n)
- Does NOT have flagella.
- Non-motile can cannot swim in water
- Is surrounded by thick cellulose wall to resist unfavorable conditions.
★ You can have comparison Q about Zygospore VS Zygote in Chlamydomonas with the same
items above.
Q: Justify or Explain: The zygote in Chlamydomonas may loses its four flagella.
Or
Q: Justify or Explain: The zygote may transform and get surrounded by thick cellulose wall.
ANS: The zygote loses its four flagella and get surrounded by thick cellulose wall to resist
unfavorable conditions, and is then called zygospore.
What is the origin of (or what is responsible for): The four haploid zoospores (in
Chlamydomonas sexual reproduction)?
ANS: Reactivation and Meiosis division of zygospore.
Q: What is responsible for the release of zoospores during sexual reproduction in
Chlamydomonas?
ANS: The splitting (rupture) of the zygospore’s cellulose wall.
Q: What are the features of zoospores produced by the zygospore?
ANS: They are haploid (n), motile, similar to the original Chlamydomonas cell, and grow into
independent organisms.
★ Do not confuse the events happening in the sexual cycle with the events happening in the
asexual cycle.
Usually, the Qs asked are easy, and if they wanted to ask you specific stuff they should mention
“in the sexual cycle” or “in the asexual cycle” between parentheses, or give you another hint
that this event is taking place in this specific cycle, for example “What are the features of

RamadhanSci 34
zoospores produced by the zygospore?” here I made it clear this the sexual cycle because I
mentioned the word zygospore.
However, we still need to learn hard/vague questions because they are possible.
Q: Draw with labelling: Reproduction in Chlamydomonas
ANS:

RamadhanSci 35
This is usually asked like this: “Draw with labelling: Sexual reproduction in Chlamydomonas” Or
“Draw with labelling: Asexual reproduction in Chlamydomonas”
The “Draw with labelling: Asexual reproduction in Chlamydomonas” presented in 2016/2 and
this was the official answer paper:
And the question “Draw with labelling: Sexual reproduction in Chlamydomonas” presented in
2014/1 and this was the official answer paper:

RamadhanSci 37
Reproduction in paramecium:
Q: Define: Paramecium
Or
Q: What are the characteristics (or features) of paramecium?
Paramecium is a ciliated protist commonly found in lakes and pond water that contains aquatic
plants and dissolved organic substances. It reproduces sexually and asexually.
Q: Where is paramecium commonly found?
ANS: Lakes and pond water that contains aquatic plants and dissolved organic substances.
Asexual reproduction in paramecium (Q/ Explain [or write down what you know about] the
Asexual reproduction in Paramecium OR Q/ What are the stages of binary fission in
paramecium ‫)وزاري‬:
Paramecium reproduces asexually by transverse binary fission, which is explained as follows:
1- Division starts with normal mitotic division of the micronucleus.
2- After the micronucleus divides, each daughter nucleus moves to opposite ends of the
Paramecium. At the same time, the macronucleus elongates, and the cytostome (mouth)
begins to form.
3- The macronucleus divides by amitosis into two nuclei, which move to opposite sides of the
Paramecium. A new mouth (oral groove) and two new contractile vacuoles appear. At the same
time, the body of the Paramecium begins to stretch and constrict (pinch) in preparation for
division.
★ NOTE: in the Arabic version they mention “ ‫اخدود‬
‫فمي‬ ” which is the “oral groove” in English.
But the English version only mentions “mouth” lol.
4- Paramecium divides into two new paramecia.
Q: What’s the type of asexual reproduction in Paramecium? )‫(وزاري‬
ANS: Transverse binary fission.
1- Micronucleus (of paramecium) )‫(وزاري‬
2- Macronucleus (of paramecium)
3- Paramecium
ANS:
1- 2n
2- Multiple sets (Polyploid).
NOTE: The macronucleus contains many copies of the genome, derived from the
micronucleus by DNA amplification and rearrangement.

RamadhanSci 38
3- Diploid (2n) with polyploid macronucleus.
NOTE: The whole paramecium is functionally diploid because it has a diploid
micronucleus, but also contains a polyploid macronucleus.
Q: Paramecium reproduces asexually by ______________.
ANS: Transverse binary fission.
Q: What is the type of division in:
1- Micronucleus
2- Macronucleus
ANS:
1- Mitosis
2- Amitosis

RamadhanSci 39
★ Possibly they want to assess the fact “cytostome” and “oral groove” are structures found in
the paramecium so pay attention to them.
Q: Draw with labelling: Binary fission in paramecium.
ANS:
Cytostome (mouth)
Micronucleus
Macronucleus

RamadhanSci 40
Sexual reproduction in paramecium:
Paramecium reproduces sexually in two ways: conjugation and autogamy (self-fertilization).
Conjugation:
Conjugation in Paramecium happens as follows:
1- Two individuals of the same species but from different strains meet and join at the side
where the mouth (oral groove) is located. They remain attached for a short time, during which a
temporary cytoplasmic bridge forms between them to allow the exchange of chromosomal
material.
2- The micronucleus in both organisms undergoes meiosis to form four nuclei, each containing
half the complete number of chromosomes (n).
3- Three of these nuclei dissolve and disappear; the fourth nucleus divides unequally by normal
division (mitosis) into two primary nuclei. Each of these nuclei contains half the complete
number of chromosomes (n) and represents the primary male and female nucleus.
4- The male nucleus in each of the two conjugated organisms is exchanged and unites with the
female nucleus to form a compact nucleus containing the complete number of chromosomes
(2n).
5- The conjugated individuals separate from each other, and each undergoes normal division
(mitosis), resulting in a total of four Paramecia — as stated in the Arabic version.
According to the English version, each Paramecium reproduces asexually by binary fission, and
four new Paramecia are formed.
★ I would go with the English version, since it matches your book and is also more scientifically
accurate.
Autogamy aka Self-fertilization (Q/ Explain [or write down what you know about] the
Autogamy or Self-fertilization OR Q/ Define: Autogamy or Self-fertilization [in paramecium]):
Autogamy is similar to conjugation, except that there is no exchange of nuclei. Instead, the two
primary micronuclei, each containing half the number of chromosomes (n), unite to form a
single identical nucleus (synkaryon). This nucleus contains identical genetic material
(homozygous), unlike in conjugation, where the genetic material is different (heterozygous).
NOTE: Although the micronucleus is typically diploid (2n), during autogamy it undergoes
meiosis, reducing the chromosome number to haploid (n). That’s why the two primary
micronuclei involved in autogamy each contain half the number of chromosomes (n) before
they fuse.

RamadhanSci 41
Q: Draw: Conjugation in Paramecium
ANS:
Q: What are chromosomes sets for each of the following:
1- Primary male nucleus in paramecium
2- Primary female nucleus in paramecium
3- Compact nucleus in paramecium )‫(وزاري‬
ANS:
1- Haploid (n).
2- Haploid (n).
3- Diploid (2n).
1- Micronucleus
2- Primary micronucleus performing autogamy
3- Identical nucleus (or synkaryon) in paramecium
4- Heterozygous compact nucleus (or united nuclei)
5- Homozygous compact nucleus (or united nuclei)
ANS:
1- Diploid (2n)
2- Haploid (n)
3- Diploid (2n)
4- Diploid (2n)
5- Diploid (2n)

RamadhanSci 42
Q: Paramecium reproduces sexually in two ways: ___________ and ___________. )‫(وزاري‬
ANS: Conjugation; Autogamy (or Self-fertilization).
Q: What is the location and function of: Cytoplasmic bridge
ANS:
Location → Between the two conjugated Paramecia, at the side where the mouth (oral
groove) is located.
Function → To allow the exchange of chromosomal material between the two individuals.
Q: What is the fate of the nuclei formed by the meiotic division of the micronucleus during
conjugation in Paramecium?
ANS:
- Meiosis of the micronucleus produces four haploid (n) nuclei.
- Three of these nuclei dissolve and disappear.
- The remaining one nucleus divides unequally by mitosis into two haploid (n) primary
nuclei:
o One becomes the primary male nucleus.
o The other becomes the primary female nucleus.
- The male nucleus is exchanged between the two conjugated individuals and fuses with
the female nucleus in the partner cell to form a diploid (2n) compact nucleus.
Q: Compare: Conjugation and Autogamy (or Self-fertilization) in paramecium )‫(وزاري‬
Or
Q: What’s the difference between conjugation and autogamy (self-fertilization) in paramecium?
ANS:
Conjugation Autogamy (self-fertilization)
The male nucleus in each of the two
conjugated organisms is exchanged and
unites with the female nucleus to form a
compact nucleus containing the complete
number of chromosomes (2n).
There is no exchange of nuclei. Instead, the
two primary micronuclei, each containing
half the number of chromosomes (n), unite
to form a single identical nucleus (synkaryon).
The compact nucleus (or united nuclei) is
heterozygous.
The compact nucleus (or united nuclei or
synkaryon or identical nucleus) is
homozygous.

RamadhanSci 43
Reproduction in Euglena:
Euglena belongs to the Protista that have flagella. It lives in lakes and flowing waters that
contain plants. Euglena exists freely under normal conditions, but becomes encysted in
unsuitable conditions.
Euglena reproduces by elongated binary fission, which occurs during both the free-swimming
and encysted stages, as follows:
1- The nucleus divides by mitotic division, and an additional flagellum is formed.
2- The cytoplasm divides laterally and gradually until the two parts are completely
separated, forming two new organisms. Sexual reproduction in Euglena is not yet
known.
Q: Define: Euglena
Or
Q: What are the characteristics (or features) of Euglena?
ANS:
Euglena belongs to the Protista that have flagella. It lives in lakes and flowing waters that
contain plants. Euglena exists freely under normal conditions, but becomes encysted in
unsuitable conditions. Euglena reproduces by elongated binary fission, which occurs during
both the free-swimming and encysted stages. Sexual reproduction in Euglena is not yet known.
Q: What is the type of reproduction for each of the following:
1- Asexual reproduction in Euglena )‫(وزاري‬
2- Sexual reproduction in Euglena
ANS:
1- Elongated binary fission.
2- Not known.

RamadhanSci 44
Q: Draw with labelling: Elongated binary fission in euglena (or Transverse binary fission in
euglena).
ANS:
Q: What is responsible for each of the following: Formation of an additional flagellum in euglena
ANS: Mitotic division of the nucleus.
Q: What is responsible for each of the following: Separation of the two euglenas from each
other (during reproduction)?
ANS: Lateral and gradual cytoplasmic division.
Q: What do the following sentences indicate: “Lateral and gradual cytoplasmic division”
ANS: Elongated binary fission in euglena. The cytoplasm divides laterally and gradually until the
two parts are completely separated, forming two new organisms.
Q: _________ reproduction in euglena is not known.
ANS: Sexual.
Reproduction in Fungi:
The kingdom Fungi contains more than one hundred thousand known species, and it is
believed that a similar number has yet to be discovered.
Fungi were previously classified as plants because they share some similarities in reproduction,
growth, and biochemistry. However, it was later discovered that fungi differ from plants in many

RamadhanSci 45
ways. For example, fungi lack photosynthetic pigments, so they are not autotrophic. Their mode
of nutrition also differs significantly from that of plants.
★ Remember: An autotroph is an organism that can make its own food by turning simple
substances like carbon dioxide into nutrients, basically, it "feeds itself.”
Q: Give an example for each of the following:
1- An autotroph
2- A kingdom that contains more than one hundred thousand known species, and it is
believed that a similar number has yet to be discovered.
ANS:
1- Plants
2- Fungi
Q: The kingdom Fungi contains _________________________ known species.
ANS: More than one hundred thousand.
Q: Justify or Explain: Fungi were previously classified as plants.
ANS: Because they share some similarities in reproduction, growth, and biochemistry.
Q: Justify or Explain: Fungi differ from plants.
ANS: Because fungi lack photosynthetic pigments, so they are not autotrophic. Their mode of
nutrition also differs significantly from that of plants.
Reproduction in Black Bread Mold:
The black bread mold belongs to the phylum Zygomycota, which includes around 1,050 species
of fungi.
Q: The black bread mold belongs to the phylum _________, which includes around _______
species of fungi.
ANS: Zygomycota; 1,050.
Sexual and asexual reproduction in black bread mold occur as follows:
1- Contact and fusion occur between hyphae containing different types of nuclei, one
positive and one negative, followed by the merging of their cytoplasm (plasmogamy).
2- Gametangia (singular: gametangium) form at the tips of each hypha (plural: hyphae),
each containing either a positive or negative nucleus. At the ends of the hyphae, nuclear

RamadhanSci 46
fusion (karyogamy, but the book loves the “nucleic integration”) occurs, where two
nuclei merge.
3- The gametangia fuse, and a pair of nuclei join together to form a zygote.
4- A thick wall forms around the zygote, and meiosis takes place.
5- The sporangiophore bears a sac called the sporangium, which splits open to release
spores. These spores contain half the original number of chromosomes because they are
formed by meiosis. When the spores land on a nutrient source (such as bread), the
asexual reproduction cycle begins, and the process repeats.
Q: What are the chromosomes sets for each of the following: (important Q)
1- The hypha of the black bread mold (i.e., before merging)
2- The hyphae after cytoplasmic plasmogamy
3- Positive nucleus (of black bread mold)
4- Negative nucleus (of black bread mold)
5- Gametangium
6- The zygote in black bread mold
7- Spores in black bread mold
8- Sporangiophore in black bread mold
9- Sporangium in black bread mold
10- Black bread mold (the individual itself)
ANS:
1- Haploid (n)
2- Dikaryotic (n + n)
NOTE: After cytoplasmic fusion but before nuclear fusion, each cell temporarily
contains two separate nuclei (one +, one −). This is called the dikaryotic phase.
3- Haploid (n)
4- Haploid (n)
5- Haploid (n)
NOTE: Each gametangium forms at the tip of a haploid hypha and contains either a +
or − nucleus.
6- Diploid (2n)
7- Haploid (n)
8- Haploid (n)
9- Haploid (n)
NOTE: In mosses (e.g., polytrichum), the sporangium is part of the diploid sporophyte
generation and produces spores by meiosis, so it's diploid. But in Rhizopus (e.g., Black
Bread Mold), the sporangium is formed on the haploid mycelium and produces spores
by mitosis (mitosis in case of asexual reproduction), so the sporangium itself is
haploid.
10- Haploid (n)

RamadhanSci 47
★ So, what are the + and – nuclei?
➔ Fungi don’t have male and female sexes like animals. Instead, they have mating types,
usually labeled + and –. These types are genetically distinct and can only fuse with the opposite
type, not with the same one. So, instead of calling them “male” and “female,” we simply refer to
them as + and – mating types.
★ The gametangium (pl.: gametangia) is the structure at the tip of each hypha, where the nuclei
(either + or −) are located. It’s the gamete-producing organ of fungi. The gametangium houses
the + or − nuclei and later fuses with another gametangium.
Think about it like this: The gametangium is like a room, and the + or − nucleus is like the person
inside.
Two rooms meet → their people come together → form a couple = zygote.
★ The sporangiophore is the stalk that holds the sporangium.
The sporangium is the sac at the tip of the sporangiophore that produces and contains the
spores.
The spores are the reproductive cells released from the sporangium.

RamadhanSci 48
Q: What is the type of reproduction of:
1- Sexual reproduction in black bread mold
2- Asexual reproduction in black bread mold
ANS:
1- Zygospore formation (zygotic sexual reproduction)
2- Sporulation (spore formation)
Q: What is the location and function for each of the following:
1- Gametangium
2- Sporangium
ANS:
1- Location → At the tip of each hypha.
Function → It houses either a positive or negative nucleus. It's where nuclear fusion
(aka nucleic integration or karyogamy) happens. It plays a key role in sexual
reproduction by forming the zygote after nuclei from two gametangia fuse.
2- Location → At the end of a sporangiophore.
Function → It acts like a sac that produces and holds spores. Once mature, it splits
open to release the spores. These spores are haploid (formed after meiosis) and can
grow into new individuals during asexual reproduction.
Q: What’s the location and function of sporangiophore?
ANS:
Location → It grows from the hypha and extends upward. It's like a stalk that holds the
sporangium.
Function → Holds and supports the sporangium. By elevating the sporangium, it makes it
easier for the spores to spread once released.

RamadhanSci 49
Q: Justify or Explain: Spores in black bread mold are haploid (n).
ANS: Because they are produced either:
- Asexually, by mitosis from haploid sporangia that grow on haploid hyphae, or
- Sexually, by meiosis inside the diploid zygospore that forms after the fusion of two
haploid gametangia.
In both cases, the resulting spores have half the full chromosome number (n).
Reproduction in plants:
The plant kingdom consists of eukaryotic, multicellular, and autotrophic organisms.
It is believed that modern plants descended from freshwater ancestors, specifically green algae,
around 500 million years ago.
Scientists support this theory based on shared features between plants and green algae. Both
groups:
- contain chlorophyll and various other pigments,
- store excess carbohydrates as starch, and
- have cell walls made of cellulose.
Q: Justify or Explain: It is believed that modern plants descended from freshwater ancestors
(or from green algae). (‫)وزاري‬
ANS: It is believed that modern plants descended from freshwater ancestors, specifically
green algae, around 500 million years ago. Scientists support this theory based on shared
features between plants and green algae. Both groups:
Q: It is believed that modern plants descended from freshwater ancestors, specifically
_________, around ________ years ago.
ANS: Green algae; 500 million.
Q: What are the shared features between plants and green algae? Explain them (‫)وزاري‬
ANS:
Both groups:

RamadhanSci 50
Q: Both plants and green algae contain chlorophyll and ______________.
ANS: Various other pigments.
Q: Both plants and green algae store excess carbohydrate as _________.
ANS: Starch.
Q: Both plants and green algae have cell walls made of __________.
ANS: Cellulose.
In the plant kingdom, alternation of generations is a clear and important feature of plant
reproduction.
It means that the complete life cycle of a plant includes two distinct stages:
- the sporophyte stage, and
- the gametophyte stage, as explained below:
Q/ Draw with labelling: Alternation
of generations in plants

RamadhanSci 51
1- Sporophyte:
This is the asexual stage that produces spores. Its cells contain the full set of chromosomes (2n).
When this stage matures, some of its cells, known as mother cells, undergo meiosis to form
spores. As a result of this division, the spores carry half the original number of chromosomes
(n), and these spores mark the beginning of the gametophyte stage.
2- Gametophyte:
This is the sexual stage of the plant life cycle, during which gametes are produced. After the
fertilization of male and female gametes, the sporophyte stage begins, this marks the
alternation of generations.
As we move up the evolutionary ladder of plants, we observe that the gametophyte becomes
progressively smaller. This reduction reaches its peak in flowering plants, where the
gametophyte is very reduced. In contrast, the sporophyte becomes more dominant, especially
in modern terrestrial plants. This shift is due to plant adaptation to life on land, as adaptations
increased, the sporophyte stage became more prominent, while the gametophyte stage was
gradually reduced.
★ Here, you can have definition questions (i.e., Define: Sporophyte or Define: Gametophyte),
or Explain or write down what you know about the (either sporophyte or gametophyte) and
possibly the whole alternation of generations (both sporophyte and gametophyte).
You can also have comparison question (‫)وزاري‬.

RamadhanSci 52
Q: Define: Alternation of generation )‫جدا‬ ‫مهم‬ ‫(وزاري‬
ANS: It is a clear and important feature of plant reproduction. It means that the complete life
cycle of a plant includes two distinct stages: the sporophyte stage, and the gametophyte
stage.
1- Sporophyte (‫)وزاري‬
2- Gametophyte
ANS:
1- Diploid (2n)
2- Haploid (n)
Q: What are the chromosomes groups for each of the following:
1- Mother cell in plants
2- Spores in plants
ANS:
1- Diploid (2n)
2- Haploid (n)
We will study three examples of plant reproduction: reproduction in mosses, ferns, and
flowering plants.
Reproduction in mosses (Polytrichum):
Reproduction in Polytrichum occurs in two stages: the sporophyte and the gametophyte.
Polytrichum is a type of moss, which represents the largest group of non-vascular plants and
includes more than 1,500 species. The process happens as follows:
1- In the mature gametophyte, the leafy stem bears antheridia (male gametangia) or
archegonia (female gametangia), both of which produce gametes.
2- The male gametes are released from the antheridia into the surrounding water, where they
swim toward the archegonia. Fertilization occurs when the male nucleus merges with the
female nucleus.
3- After fertilization, a zygote is formed, and the sporophyte begins to develop inside the
archegonium.

RamadhanSci 53
4- The gametic tissue develops fully and bears the sporangium, within which meiosis occurs to
produce spores that contain half the full number of chromosomes (n).
NOTE: In the Arabic version of the book, the book mentions “‫البوغي‬ ‫”النسيج‬ which is best
translated into “sporogenous tissue” or “spore-producing tissue,” but in the English version it
simply mentions “Gametic tissue,” I’m just being OCD here for exam purposes and I think you
should be familiar with all terminologies.
5- With the help of wind, the capsule (cover) opens, and the spores are then released and
spread through the air.
6- The spores grow into male or female gametophytes, starting as a structure called the
protonema. This represents the first stage of the male or female gametophyte.
Q: Give an example of each of the following:
1- Moss plant
2- Non-vascular plant
3- A non-vascular plant with more than 1500 species
ANS:
1- Polytrichum
2- Mosses (e.g., polytrichum)
3- Polytrichum (which is a moss plant).
Q: Define: Polytrichum
Or
Q: What are the characteristics (or features) of the Polytrichum
ANS: Polytrichum is a type of moss, which represents the largest group of non-vascular plants
and includes more than 1,500 species. Reproduction in Polytrichum occurs in two stages: the
sporophyte and the gametophyte.
1- Archegonia )‫(وزاري‬.
2- Female gametangium
3- Antheridia
4- Male gametangium
5- Zygote of polytrichum (or of mosses)
6- Gametic tissue in EN / Sporogenous tissue in AR
7- Sporangium in polytrichum
8- Protonema

RamadhanSci 54
ANS:
1- Haploid (n)
2- Haploid (n)
3- Haploid (n)
4- Haploid (n)
5- Diploid (2n)
6- Diploid (2n)
NOTE: Gametic tissue develops within the sporophyte, and undergoes meiosis to form
spores.
7- Diploid (2n)
NOTE: In mosses (e.g., polytrichum), the sporangium is part of the diploid sporophyte
generation and produces spores by meiosis, so it's diploid. But in Rhizopus (e.g., Black
Bread Mold), the sporangium is formed on the haploid mycelium and produces spores
by mitosis, so the sporangium itself is haploid.
8- Haploid (n)
Q: What is the function of each of the following:
1- Archegonia )‫(وزاري‬
2- Antheridia
ANS:
1- Produce female gametes
2- Produce male gametes
Q: Justify or Explain: spores in polytrichum are haploid (n).
ANS: Because they’re formed by meiosis that occurs in the diploid sporangium.
Q: Regarding the reproduction in mosses (or in polytrichum), the leafy stem bears _________ or
_________.
ANS: Antheridia (male gametangia); Archegonia (female gametangia).
Q: Regarding the reproduction in mosses (or in polytrichum), the ______ bears antheridia or
archegonia.
ANS: Leafy stem.
Q: What is responsible of each of the following:
1- Opening the cover (capsule) of the sporangium in polytrichum (or moss)
)‫لهذا‬ ‫مشابه‬ ‫وزاري‬ ‫(سؤال‬
2- Spreading of the spores of the polytrichum (or moss) )‫لهذا‬ ‫مشابه‬ ‫وزاري‬ ‫(سؤال‬

RamadhanSci 55
ANS:
1- The help of wind
2- Air (or Air current)
Q: What is the location of each of the following:
1- Antheridia in mosses (or polytrichum)
2- Archegonia in mosses (or polytrichum)
ANS:
1- Antheridia (male gametangia) are located on the leafy stem of the mature gametophyte.
2- Archegonia (female gametangia) are located on the leafy stem of the mature
gametophyte.
★ So, both Antheridia (male gametangia) and archegonia (female gametangia) in mosses are
located on the leafy stem of the mature gametophyte.
Reproduction in Ferns:
Ferns are a type of seedless vascular plant, comprising around 12,000 species.
Note: The Arabic textbook mentions just over 1,150 species, which is quite the understatement.
Reproduction in ferns occurs in two stages: the sporophyte and the gametophyte, as follows:
1- Sporophyte is the dominant stage in the life cycle of ferns. Sporangia develop on the
underside of the leaves (lower surface of leaves).
2- Spores are formed inside the sporangium through meiosis, so they carry half the full number
of chromosomes (n). When the sporangium opens, the spores are released.
3- The spores grow into the gametophyte, which is represented by a structure called the
prothallus. It is a heart-shaped, green structure that carries the archegonium (female organ)
and the antheridium (male organ). From its pointed end, structures called rhizoids grow, which
anchor the prothallus to the ground.
NOTE: "‫الجذور‬ ‫"أشباه‬ = Rhizoids ➔ they’re root-like structures, not true roots, used for
attachment and limited absorption.
4- Fertilization takes place in a moist environment, where the sperm swim through water to
reach the egg inside the archegonium.
5- The zygote, formed by fertilization inside the archegonium, develops into a young
sporophyte. The first leaf emerges above the prothallus, while roots grow downward, marking
the beginning of the sporophyte stage.
1- Seedless vascular plant

RamadhanSci 56
2- Seedless vascular plant, comprising around 12,000 species (or if the exam was hyper-
cringe: Seedless vascular plant, comprising around 1,150 species)
3- A structure in ferns that grows rhizoids
4- A heart-shaped structure in ferns
5- A structure in ferns carries archegonium
6- A structure in ferns carries antheridium
7- The dominant stage in the life cycle of ferns
ANS:
1- Ferns
2- Ferns
3- Prothallus
4- Prothallus
5- Prothallus
6- Prothallus
7- Sporophyte
Q: What is the location and function of rhizoids?
ANS:
Location → Rhizoids grow from the pointed end of the prothallus.
Function → They serve to anchor the prothallus to the ground. Rhizoids are root-like structures
but not true roots, so they mainly provide attachment and may have limited absorption ability.
Q: Define: Rhizoids
ANS: Root-like structures growing from the pointed end of the prothallus, anchoring it to the
ground and providing limited absorption.
What is the location of each of the following:
1- The first leaf in the sporophyte of ferns
2- The roots in the sporophyte of ferns.
ANS:
1- Above the prothallus.
2- Below the prothallus, growing downward.
Q: __________ is the dominant stage in the life cycle of ferns.
ANS: Sporophyte.

RamadhanSci 57
Q: Define: Prothallus )‫(وزاري‬
ANS:
Is a heart-shaped, green structure that carries the archegonium (female organ) and the
antheridium (male organ). From its pointed end, structures called rhizoids grow, which anchor
the prothallus to the ground.
NOTE: To be specific, the antheridium is located at the pointed end of the prothallus, and the
archegonium is located at the broad end of the prothallus.
Q: Justify or Explain: Spores produced in the sporangia of ferns are haploid (n). )‫(وزاري‬
ANS: Because they are formed by meiosis.
Q: Ferns are a type of ________ vascular plant, comprising around 12,000 species.
ANS: Seedless.
Q: Ferns are a type of seedless, _________ plant, comprising around 12,000 species.
ANS: Vascular.
Q: Mosses are _______ plants, and ferns are ______ plants. )‫(وزاري‬
ANS: Non-vascular; Vascular.
NOTE: The plural form of antheridium is antheridia, and the plural form of archegonium is
archegonia.
1- Antheridia in ferns
2- Archegonia in ferns
ANS:
1- Antheridia are located on the prothallus
2- Archegonia are located on the prothallus
★ So, both Antheridia and archegonia in ferns are located on the prothallus.
REMEMBER:
- Both Antheridia (male gametangia) and archegonia (female gametangia) in mosses are
located on the leafy stem of the mature gametophyte.
- Both Antheridia and archegonia in ferns are located on the prothallus.

RamadhanSci 58
Q: Male gametangia in ferns are called _________, and female gametangia are called
_______. )‫(وزاري‬
ANS: Antheridia; Archegonia.
Q: Prothallus carries male gametangium called _______, and female gametangium called
________. )‫(وزاري‬
ANS: Antheridium; Archegonium.
Q: What is the location of each of the following: Sporangia in ferns. )‫(وزاري‬
ANS: The underside of the fern leaves (lower surface of leaves).
What is responsible for each of the following: Release of spores in ferns )‫(وزاري‬
ANS: Opening of the sporangium.
What’s the origin of:
1- Prothallus )‫(وزاري‬
2- Gametophyte in ferns )‫(وزاري‬
ANS:
1- Spore growth
2- Spore growth (the gametophyte is represented by the prothallus)
Q: What are the chromosomes sets for each of the following: Prothallus (in ferns). (important
Q)
ANS: Haploid (n), WHY (Justify)? ➔ Because the prothallus is the gametophyte stage in the
fern life cycle. It develops from a spore, which is produced by meiosis and thus has half the
number of chromosomes compared to the sporophyte.
★ Prothallus (gametophyte) → develops from the spore → haploid (n).
Q: Compare: Sporophyte and gametophyte in ferns. )‫(وزاري‬
ANS:
Sporophyte Gametophyte
Is the dominant stage in the life cycle of
ferns.
Is NOT the dominant stage.
Sporangia develop on the underside of the
leaves (lower surface of leaves).
Gametangia (antheridia and archegonia) are
located on the prothallus.
Sporophytes are diploid (2n) because they
represent the asexual stage.
Gametophytes are haploid (n) because they
represent the sexual stage.

RamadhanSci 59
Forms by the fertilized egg (the zygote). The
first leaf emerges above the prothallus, while
roots grow downward
Forms by the growth of the spores into
prothallus.
Q: Justify or Explain: Sporophytes are diploid (2n). (important Q)
ANS: Because they represent the asexual stage. They develop from the zygote, which is formed
by the fusion of two haploid gametes (egg and sperm), each carrying n chromosomes. This
fusion restores the diploid number (2n) of chromosomes.
Q: Justify or Explain: Gametophytes are haploid (n). (important Q)
ANS: Because they represent the sexual stage. They develop from spores that are produced by
meiosis in the sporophyte. Meiosis reduces the chromosome number by half, so the resulting
spores and the gametophyte that develops from them carry only one set of chromosomes (n).
★ This justification works for all plants that exhibit alternation of generations (like mosses,
ferns, and flowering plants).
Q: Justify or Explain: Reproduction in ferns needs wet (or moist) environment.
ANS: Because fertilization takes place in a moist environment, as sperm require water to swim
toward the egg inside the archegonium.
Reproduction in flowering plants:
The flower is the reproductive organ in flowering plants. The continuity of plant life depends on
reproduction.
The flower is a specialized branch that bears modified leaves involved in sexual reproduction,
leading to the formation of fruits and seeds. The flower contains parts that are directly involved
in reproduction (called essential parts) and others that are not directly involved (called non-
essential parts).
Flowers develop from buds similar to those in green (vegetative) plants, but they differ in their
growth pattern. In flowering plants, the stem or axis of the flower does not elongate
significantly. As a result, the floral organs appear close to one another and are not separated by
visible stem segments along the floral axis.
1- Reproductive organ in flowering plants

RamadhanSci 60
2- The process that the continuity of plant life depends on
ANS:
1- The flower
2- Reproduction
Q: The essential parts of the flower are ______ involved in reproduction, and the non-essential
parts of the flower are ______ involved in reproduction.
ANS: Directly; Indirectly.
Q: Flowers develop from _______ similar to those in green (vegetative) plants.
ANS: Buds.
Q: What is the origin of flowers?
ANS: Buds.
Q: Justify or Explain: Flowering plants and green (vegetative) plants are different even though
both develop from buds.
ANS:
Although both flowering and green (vegetative) plants develop from buds, they differ in their
growth pattern. In flowering plants, the floral axis does not elongate significantly, so the floral
organs remain close to each other and are not separated by visible stem segments. In
contrast, vegetative buds produce shoots with elongated internodes, where leaves are spaced
apart along the stem.
Q: Justify or Explain: Floral organs appear close to one another. )‫(وزاري‬
ANS: Because the floral axis in flowering plants does not elongate significantly, the floral
organs remain clustered together without visible stem segments separating them.
Q: What is responsible for each of the following: Floral organs being close to one another.
ANS: Lack of elongation in the floral axis.
Q: Define: Flower. (possible Q)
ANS: The flower is the reproductive organ in flowering plants. The continuity of plant life
depends on reproduction. The flower is a specialized branch that bears modified leaves
involved in sexual reproduction, leading to the formation of fruits and seeds. The flower
contains parts that are directly involved in reproduction (called essential parts) and others
that are not directly involved (called non-essential parts). Flowers develop from buds similar
to those in green (vegetative) plants, but they differ in their growth pattern. In flowering
plants, the stem or axis of the flower does not elongate significantly. As a result, the floral

RamadhanSci 61
organs appear close to one another and are not separated by visible stem segments along the
floral axis.
Q: Flowers differ from green (vegetative) plants in that they don’t ___________. )‫(وزاري‬
ANS: Elongate their stem (flower axis).
Essential parts of the flower ➔ Pistil and Stamens.
Non-essential parts of the flower → Sepals and petals.
Flowers consist of four main parts, as follows (Q/ List only: Flower parts):
1- Sepals (collectively called the calyx). Non-essential.
2- Petals (collectively called the corolla). Non-essential.
3- Stamens, consists of two parts: Anther and Filament. Stamens is essential part of the
flower.
4- Pistil, consists of the following parts: Ovary, Style, and Stigma. Pistil is essential part of
the flower.
1- Sepals (Q/ Define: Sepals. Or Q/ Define: Calyx. Or Q/ What are the characteristics [or
features] of sepals [or calyx]):
Sepals are collectively known as the calyx, which protects the flower bud before it opens. They
are usually green, though sometimes colorful, and remain attached to the lower part of the
flower (the receptacle). Sepals are non-essential part of the flower.
NOTE: ‫التخت‬ = Receptacle.
Q: Sepals are collectively known as _______.
ANS: Calyx.
Q: _______ are collectively known as calyx.
ANS: Sepals.
1- Part of the plant that remains attached to the receptacle.
2- Part of the plant that are usually green, and can sometimes be colorful.
ANS:
1- Petals (calyx)
2- Petals (calyx)

RamadhanSci 62
Q: Petals remain attached to the ____________.
ANS: Lower part of the flower (the receptacle).
Q: Petals are usually _____ in color, though sometimes ______.
ANS: Green; Colorful.
Q: What is the location and function of petals (calyx)?
ANS:
Location → Attached to the lower part of the flower (the receptacle).
Function → Protects the flower bud before it opens. )‫(وزاري‬
2- Petals (Q/ Define Petals [or corolla]. Or Q/ What are the characteristics [or features] of
petals [or corolla]):
Petals are collectively known as the corolla. They vary in shape, size, and color among different
plants. Typically, the number of petals equals the number of sepals or is double that. For
example, the iris has three sepals and three petals, while the rose has many more petals than
sepals. Petals play an important role in attracting insects that aid in pollination. However, both
sepals and petals do not directly participate in sexual reproduction or seed formation.
Q: Give an example of non-essential part of the flower
Or
Q: Give an example of plant part that does not directly participate in sexual reproduction
ANS: Sepals and Petals.
Q: Petals are collectively known as _______.
ANS: Corolla.
Q: _______ are collectively known as corolla.
ANS: Petals.
Q: petals vary in shape, size, and color among ________.
ANS: Different plants.
Q: Typically, the number of petals equals the number of sepals or ___________.
ANS: Is double that.

RamadhanSci 63
1- Flower has three sepals and three petals
2- Flower has petals more than sepals.
3- Flower has equal numbers of sepals and petals
ANS:
1- Iris
2- Rose
3- Iris
Q: What is location and function of petals (corolla)?
ANS:
Location → Above the sepals and surround the reproductive organs of the flower.
Function → Attract insects that aid in pollination.
Q: Justify or Explain: Sepals and petals are non-essential structures in the flower. )‫(وزاري‬
ANS: Because both sepals and petals do not directly participate in sexual reproduction or seed
formation.
Q: _______ and ______ are non-essential structures in the flower. )‫(وزاري‬
ANS: Sepals; Petals.
3- Stamens (Q/ Define: Stamens):
Stamens represent the male reproductive part of the flower and consist of two main parts: the
anther and the filament. The anther is typically cylindrical or elliptical in shape and contains
pollen grains. It is supported by a thin stalk called the filament. Stamens are usually separate
(free), but in some plants, they may be fused together, either by their anthers or filaments. The
number of stamens varies between plant species.
Q: The number of stamens varies between _________.
ANS: Plant species.
1- The male reproductive part of the flower.
2- Cylindrical or elliptical structure contains pollen grain. Or, Cylindrical (or elliptical)
structure of the stamens (or in the flower)

RamadhanSci 64
3- Structure of stamens (or in the flower) contains pollen grain
4- A thin stalk that holds (or supports) the anther.
ANS:
1- Stamens
2- Anther
3- Anther
4- Filament
Q: Define: Anther
ANS: The anther is part of stamens in flowers. The anther is typically cylindrical or elliptical in
shape and contains pollen grains. It is supported by a thin stalk called the filament.
Q: Stamens are usually __________, but in some plants they may be ______ together either by
their anthers or filaments.
ANS: Separate (free); Fused.
Q: What is the location and function of:
1- Stamens
2- Anther
3- Filament (kinda vague cuz literally there are 999 other structures/entities we can call
filaments, so they should write “filament of stamens”)
ANS:
1- Location → Surround the pistil, typically arranged in a circle inside the petals.
Function → Represent the male reproductive organ of the flower; responsible for
producing and delivering pollen.
2- Location → Part of the stamen, sitting at the top of the filament.
Function → Contains pollen sacs where pollen grains (male gametes) are produced and
stored. )‫(وزاري‬
3- Location → Part of the stamen, beneath the anther.
Function → Holds and supports the anther in an elevated position to expose it to
pollinators or wind for effective pollen transfer.
Q: List only: Parts of stamen
ANS:
1- Anther

RamadhanSci 65
2- Filament
★ You can have a question format telling you to List + mention the function of the stamen parts.
You can also expect Qs asking you to list + mention the location, or to list + explain each part.
Just a quick note before we dive into the definition of pistil.
Pistil vs Carpel:
A carpel is the basic unit of the female reproductive part of a flower. It consists of three parts:
stigma, style, and ovary.
A collection of carpels (whether fused or separate) is referred to as a pistil.
This distinction isn’t emphasized in the textbook, but I’m throwing it in here just in case they
decide to get ultra-annoying and toss a cringe question on the exam. You're welcome.
4- Pistil (Q/ Define: Pistil):
The pistil (or carpel) is the female part of the flower, and it consists of the following parts:
- Ovary: This is the swollen lower part of the pistil. It contains the ovules, which are
attached to the ovary wall by a short stalk (or short neck) called the funiculus.
- Style: It is cylindrical, thin, and hollow in shape. It connects the ovary to the upper part
called the stigma.
- Stigma: This is the terminal (topmost) part of the pistil. It is often swollen or enlarged. It
may have hair-like structures (fimbriae or fringes) and a rough surface, and it is usually
covered with a sticky secretion to help capture and retain pollen grains.
We should note that flower structures vary among different plants. For example, monocots and
dicots have distinct floral arrangements, and even within the same group, flowers can differ in
their structure.
Q: List only: The parts of pistil (or carpel)
ANS:
1- Ovary
2- Style
3- Stigma
★ You can have a question format telling you to List + mention the function of the pistil parts
)‫(وزاري‬.
You can also expect Qs asking you to list + mention the location, or to list + explain each part.
Q: What’s the location and function of each of the following:

RamadhanSci 66
1- Pistil (or carpel)
2- Ovary of pistil (or of flower, or of carpel)
3- Style
4- Stigma )‫(وزاري‬
ANS:
1- Location → Central part of the flower, usually surrounded by stamens.
Function → Female reproductive organ; responsible for producing ovules, receiving
pollen, and developing seeds and fruits.
2- Location → The swollen, basal (lower) part of the pistil.
Function → Contains ovules; after fertilization, it develops into the fruit.
3- Location → The slender, cylindrical stalk connecting the ovary to the stigma.
Function → Supports the stigma and provides a passage for pollen tubes to grow from
the stigma to the ovary.
4- Location → The topmost part of the pistil.
Function → Receives and traps pollen grains; sticky surface helps retain pollen, which
then passes through it to the style and eventually reaches the ovary for fertilization.
Q: What is responsible for each of the following: Capturing and retaining the pollen grains on
the stigma?
ANS:
- A sticky secretion that holds the pollen in place,
- Fimbriae (hair-like structures) that trap or guide the pollen,
- And a rough surface that provides extra grip and increases the chances of pollen
adhesion.
Q: What is responsible for each of the following: Attachment of the ovules to the ovary wall.
ANS: a short stalk (or short neck) called the funiculus.
NOTE: The term ovule specifically refers to a reproductive structure in plants, so it's generally
unnecessary to add "in plants" after it. It's assumed that you know the distinction between an
ovule (plant structure) and an ovum (animal egg cell).

RamadhanSci 67
Q: The _______ are attached to the ovary wall by a short stalk (or short neck) called the
funiculus.
ANS: Ovules.
Q: The ovules are attached to the ovary wall by a short stalk (or short neck) called the
________.
ANS: Funiculus.
Q: The ovules are attached to the ________ by a short stalk (or short neck) called the funiculus.
ANS: Ovary wall.
Q: The ovules are attached to the ovary wall by a ____________ called the funiculus.
ANS: Short stalk (or short neck).
Q: What do the following sentences indicate: Short neck called the funiculus.
ANS: The structure that attaches the ovules to the ovary wall.
Q: Draw with labelling: Structure of flower
ANS:

RamadhanSci 68
They can ask you to draw only one part of this illustration, for example, “Draw with labelling:
Pistil (or carpel) is ‫وزاري‬.“
Also, possible to ask you to draw two or more parts, for example, “Draw with labelling: Stamens,
Corolla, and calyx (omitting the pistil).”
Q: Compare: Monocotyledons and Dicotyledons )‫(وزاري‬
ANS:
Monocotyledons Dicotyledons
Have one embryonic leaf Have two embryonic leaves
They have floral parts in threes or in
multiples of three.
The flower parts occur in fours (Tetramerous),
fives (Pentamerous), or multiples of four or
five.
Monocot pollen grains typically have a single
pore.
Dicots pollen grains have three pores.
Generally herbaceous plants Generally herbaceous or woody plants
Parallel-veined leaves "Reticulate-veined leaves" or "Net-veined
leaves"
Have adventitious (fibrous) roots Have taproot system"
Flower terminology:
Property Flower
Complete flower A flower that has all four main parts: sepals,
petals, stamens, and pistils.
Incomplete flower A flower that is missing one or more of the
four main parts.
Perfect flower aka Hermaphrodite flower,
Bisexual flower, or Monoecious plant
A flower that has both stamens (male part)
and pistil (female part) in the same flower.
Imperfect flower aka Unisexual flower, or
Dioecious plant
A flower that has either stamens (male part)
or pistils (female part), but not both in the
same flower.
Sterile flower A flower that lacks both stamens and pistils.
Inflorescence Flowers grouped or bundled together.

RamadhanSci 69
Composite flower Appears as a single flower, but is actually
made up of many small individual flowers.
NOTE1: Perfect flower = Hermaphrodite flower = Bisexual flower, but not really = Monoecious
plant.
Monoecious plant = a plant that has separate male and female flowers, but both types are on
the same plant. The flowers of the monoecious plant are actually imperfect ☺.
Perfect flower = a single flower that has both male and female parts (stamens + pistils in the
same flower). Also called hermaphrodite flower.
NOTE2: Imperfect flower = Unisexual flower, but not really = Dioecious plant.
Imperfect flower has only stamens OR only pistils.
Dioecious plant has only male or only female flowers on separate plants.
Dioecious plants always have imperfect flowers.
∴ Dioecious plants have imperfect flowers but the rule is not to be in the same plant
Dioecious
plants
Actually imperfect flower
Monoecious plant

RamadhanSci 70
NOTE3: You can have questions from this table with the following Q formats:
- Blank Qs ➔ A flower that lacks both stamens and pistils is called _______. ANS: Sterile
flower.
- Definition Qs ➔ Define: Imperfect flower. ➔ ANS: A flower that has either stamens
(male part) or pistils (female part), but not both in the same flower.
- Give an example Qs ➔ Give an example for each of the following: A flower that appears
as a single flower, but is actually made up of many small individual flowers. ➔ ANS:
Composite flower.
- Justification/Explanation Qs ➔ Justify or Explain: Composite flower is not considered an
individual (single) flower ➔ ANS: Because composite flower appears as a single flower,
but is actually made up of many small individual flowers.
- Characteristics/Features Qs ➔ What are the characteristics/features for each of the
following: Complete flower ➔ ANS: Has all four main parts: sepals, petals, stamens, and
pistils.
- Comparison Qs ➔ Compare: Incomplete flower and Perfect flower.
ANS:
Incomplete flower Perfect flower
A flower that is missing one or more of the
four main parts.
A flower that has both stamens (male part)
and pistil (female part) in the same flower.
NOTE4: The whole flower is considered diploid (2n). The entire flower, being part of the
sporophyte, is diploid (2n).
So, if they ask you about the chromosomes sets:
Flower → 2n.
Sepals (calyx) → 2n.

RamadhanSci 71
Petals (corolla) → 2n.
Stamens → 2n.
Anther → 2n.
Filament → 2n.
Pistil (or carpel) → 2n.
Ovary (of flower) → 2n.
Ovule → 2n.
Style → 2n.
Stigma → 2n.
First: The formation of pollen grains and ovules.
Anther and pollen production:
Anther is made of two elongated lobes (or segments), and between them lies an inner tissue
that extends from the base of the anther to the top. This tissue surrounds the vascular bundle.
NOTE ‫وزاري‬: In the Arabic version, this "inner tissue" is described as "‫رابط‬ ‫"نسيج‬, which might
make you think of connective tissue, but don't be fooled! Connective tissue (CT) is an animal-
specific term and doesn’t apply to plants. In plants, the corresponding structure is most likely
parenchyma tissue ‫وزاري‬, which is a common type of ground tissue that fills spaces, supports
structures, and may store nutrients or assist with other functions. But for consistency with the
book, we’ll still refer to it as “connecting tissue.”
Each lobe of the anther consists of two compartments (or chambers), and each compartment is
called a pollen sac or microsporangium. The pollen sac contains pollen grains. When the anther
matures, the connecting tissue between its two compartments breaks down, causing the two
compartments to merge into a single chamber.
At this point, the anther opens to the outside through a longitudinal (vertical) slit, allowing the
pollen grains to be released into the environment.
Initially, the pollen sacs contain microspore mother cells, which have the diploid (2n) number of
chromosomes. These cells undergo meiosis to produce four haploid (n) microspores, each
containing half the chromosome number. Afterward, the four microspores separate from each
other and develop into distinct shapes that vary depending on the plant species.
The nucleus of the microspore divides by mitosis, and each resulting nucleus becomes
surrounded by cytoplasm, forming two distinct cells: a tube cell and a generative cell.
This two-celled structure is referred to as the pollen grain, and it represents the immature male
gametophyte.
Pollen grains are released from the anther in large numbers, approximately hundreds per
anther.

RamadhanSci 72
Each pollen grain is surrounded by a thick outer wall, often with horn-like projections or a rough
surface, and varies in shape depending on the plant species.
Pollen grains also contain one or more thin regions in their wall known as germination pores.
Q: Pollen grains represent _____________.
ANS: Immature male gametophyte.
Q: Explain how pollen grains are formed. )‫(وزاري‬
ANS: Initially, the pollen sacs contain microspore mother cells, which have the diploid (2n)
number of chromosomes. These cells undergo meiosis to produce four haploid (n)
microspores, each containing half the chromosome number. Afterward, the four microspores
separate from each other and develop into distinct shapes that vary depending on the plant
species.
The nucleus of the microspore divides by mitosis, and each resulting nucleus becomes
surrounded by cytoplasm, forming two distinct cells: a tube cell and a generative cell.
This two-celled structure is referred to as the pollen grain, and it represents the immature
male gametophyte.
Q: What is the type of tissue of each of the following: The tissue connecting the two lobes of
the anther. )‫(وزاري‬
ANS: Parenchyma tissue (or Connecting parenchyma tissue).
Q: Pollen sac represents ________________. )‫(وزاري‬
ANS: Microsporangium.
Q: What’s the location and function of pollen sac? )‫(وزاري‬
ANS:
Location → Anther.
Function → Contains pollen grains.
Q: What’s the location and function of microsporangium? )‫وزاري‬ ‫لسؤال‬ ‫(مشابه‬
ANS:

RamadhanSci 73
Location → Anther.
Function → Contains pollen grains.
Q: what are the chromosomes sets for each of the following: )‫جدا‬ ‫ومهم‬ ‫وزاريات‬ ‫كلهن‬ ‫(تقريبا‬
1- Microspore mother cell
2- Microspore
3- Tube cell
4- Generative cell
5- Nucleus of microspore
6- Nucleus of tube cell
7- Nucleus of generative cell
8- Pollen grain
9- Immature male gametophyte
10- Microsporangium (a.k.a. Pollen Sac)
11- Anther
12- The flower (as a whole)
ANS:
1- Diploid (2n)
2- Haploid (n)
3- Haploid (n)
4- Haploid (n)
5- Haploid (n)
6- Haploid (n)
7- Haploid (n)
8- Haploid (n)
9- Haploid (n)
10- Diploid (2n)
NOTE: It’s a tissue part of the sporophytic generation (the flower's anther). It produces
microspore mother cells, which are also diploid and divide by meiosis.
11- Diploid (2n)
NOTE: The anther is part of the sporophytic generation (the flower as a whole is
diploid), and it contains diploid tissues like the microsporangia (pollen sacs), which
produce haploid microspores via meiosis.
12- Diploid (2n)
Q: What’s the origin of (or what’s responsible for) each of the following:

RamadhanSci 74
1- Tube cell )‫(وزاري‬
2- The nucleus of the generative cell )‫(وزاري‬
3- Generative cell
4- The nucleus of the tube cell
5- The four microspores
ANS:
1- The nucleus of the microspore
5- Meiosis of microspore mother cell.
Q: Justify or Explain: Microspore is haploid (n). )‫(وزاري‬
ANS: Because it results from meiosis of microspore mother cell.
Q: Pollen grains contain one or more thin regions in their wall known as ____________.
ANS: Germination pores.
Q: What’s the location of germination pore?
ANS: In the wall of the pollen grain.
Ovary and egg production:
The pistil, including the ovary, is formed from one or more fused leaf-like structures called
carpel leaves. These carpels are considered megasporophylls (female spore-bearing leaves).
The ovules, which contain the egg cells, are attached to the ovary wall and represent the
megasporangia (female spore sacs).
The egg starts developing inside a small mass called the nucellus, which is connected to the
ovary wall by a short stalk called the funiculus. The nucellus is surrounded by one or more
layers of protective cells (integuments) called ovary cover cells. These layers grow from the base
of the nucellus and completely cover it, except at the top where they leave a small opening
called the micropyle.
A compound cell grows inside the nucellus called the megaspore mother cell. This cell
undergoes meiosis to produce four megaspores with half the number of chromosomes (n)
arranged in a straight line.

RamadhanSci 75
Three of the megaspores degenerate, and the remaining one becomes the functional (or
effective) megaspore.
This functional megaspore represents the immature female gametophyte, which in
angiosperms (Magnoliophyta) is called the embryo sac.
NOTE: Angiosperms (also called Magnoliophyta) are a major group (a phylum) of plants
known as flowering plants. Their seeds are enclosed inside a fruit, which is why they’re called
"‫البذور‬ ‫"مغطاة‬ (covered seeds).
This embryo sac grows in size as both its cytoplasm and nucleus increase, occupying most of the
ovule.
Three successive mitotic divisions occur in the nucleus of the embryo sac, resulting in eight
nuclei. Of these, three nuclei group near the micropyle, three gather at the opposite end, and
two remain in the center.
Three nuclei at the micropyle end become enclosed by membranes to form cells. The central
nucleus develops into the egg cell, while the two nuclei on either side form the two synergid
cells. The nuclei on the side opposite the micropyle within the embryo sac are also enclosed by
membranes, forming the antipodal cells. The two central nuclei form the polar nuclei. At this
stage, the embryo sac represents the mature female gametophyte.
When the female gametophyte matures, the mature egg forms within the mature embryo sac,
surrounded by the nucellus and its membranes. The funiculus, which connects the ovule to the
ovary wall, curves downward so that the micropyle is positioned near the funiculus, although
this relative position can vary.
Q: Describe the steps in the formation of the mature embryo sac, starting from the
megaspore mother cell. )‫(وزاري‬
ANS: A compound cell grows inside the nucellus called the megaspore mother cell. This cell
undergoes meiosis to produce four megaspores with half the number of chromosomes (n)
arranged in a straight line. Three of the megaspores degenerate, and the remaining one
becomes the functional (or effective) megaspore. This functional megaspore represents the
immature female gametophyte, which in angiosperms (Magnoliophyta) is called the embryo
sac. This embryo sac grows in size as both its cytoplasm and nucleus increase, occupying most
of the ovule. Three successive mitotic divisions occur in the nucleus of the embryo sac,
resulting in eight nuclei. Of these, three nuclei group near the micropyle, three gather at the
opposite end, and two remain in the center. Three nuclei at the micropyle end become
enclosed by membranes to form cells. The central nucleus develops into the egg cell, while
the two nuclei on either side form the two synergid cells. The nuclei on the side opposite the
micropyle within the embryo sac are also enclosed by membranes, forming the antipodal
cells. The two central nuclei form the polar nuclei. At this stage, the embryo sac represents
the mature female gametophyte.

RamadhanSci 76
Q: The mature egg within the mature embryo sac is composed of _________, _________, and
________. )‫(وزاري‬
ANS: The surrounding nucellus; The membranes; The funiculus.
Q: Carpel leaves represent __________, and the ovules attached to the ovary wall represent
the ___________. )‫(وزاري‬
ANS: Megasporophylls; Megasporangia.
Q: What’s the location of micropyle? )‫(وزاري‬
ANS: At the top of the nucellus.
NOTE for Clarification: In the Arabic version, it says that the integuments (‫خثرية‬ ‫)خاليا‬ that are
called ovary cover cells (‫البويض‬ ‫)اغلفة‬ cover the ovule (‫)البويضة‬, and that the micropyle is located
in the ovule, and yes, this is the official answer in Arabic exams.
However, for scientific accuracy + according to your English textbook: the integuments actually
grow from the base of the nucellus and cover the nucellus, not the ovule as a whole. The
micropyle is the small opening left at the top of these integuments, so its more accurate
location is: "at the top of the nucellus."
∴ The official answer according to your book should be: “At the top of the nucellus.”
Q: Define: Nucellus. )‫(وزاري‬
ANS: The nucellus is a small mass (or hump) connected to the ovary wall by a short stalk called
the funiculus. The nucellus surrounds the mature egg in the mature embryo sac. The nucellus
itself is surrounded by one or more layers of protective cells (integuments) called ovary cover
cells. These layers grow from the base of the nucellus and completely cover it, except at the top
where they leave a small opening called the micropyle.
Q: What are the components of mature egg? )‫(وزاري‬
ANS:
1- Mature embryo sac
2- Covered by membrane
3- Nucellus
4- Funiculus

RamadhanSci 77
Q: What’s the location of megaspore mother cell? )‫(وزاري‬
ANS: Inside the nucellus.
Q: What are the chromosome sets for each of the following:
1- Megaspore mother cell → Diploid (2n)
2- Megaspore → Haploid (n)
3- Pistil → 2n
4- Carpel leaves → 2n
5- Ovary → 2n
6- Megasporophylls → 2n (= carpel leaves)
7- Flower → 2n
8- Ovule → 2n
9- Megasporangia → 2n (ovules = megasporangia)
10- Nucellus → 2n (it's part of the ovule tissue and derived from the sporophyte)
11- Funiculus → 2n (a stalk from ovary wall = sporophyte tissue)
12- Ovary cover cells (integuments) → 2n (integuments develop from ovary wall =
sporophytic)
13- Membranes covering the nucellus → 2n (derived from integuments, so also 2n)
14- Micropyle → 2n (it's just a physical gap in the integuments, which are 2n)
15- Embryo sac → n )‫(وزاري‬
16- Mature embryo sac → n
17- Functional (effective) megaspore → n )‫الفعال‬ ‫البوغ‬ :‫الصيغة‬ ‫بهذي‬ ‫اجة‬ ‫بالعربي‬ ،‫مهم‬ ‫(وزاري‬

RamadhanSci 78
18- Immature female gametophyte → n
19- Mature female gametophyte → n
20- Egg cell (of flowering plant) → n
21- Synergid cells → n
22- Antipodal cells → n )‫(وزاري‬
23- Mature egg (of flowering plant) → n
24- Polar nucleus (A single polar nucleus) → n
25- Polar nuclei (both nuclei together/fused) → 2n
Q: How is the mature female gametophyte formed? )‫لهذا‬ ‫مشابه‬ ‫وزاري‬ ‫(سؤال‬
ANS: Three successive mitotic divisions occur in the nucleus of the embryo sac, resulting in eight
nuclei. Of these, three nuclei group near the micropyle, three gather at the opposite end, and
two remain in the center. Three nuclei at the micropyle end become enclosed by membranes to
form cells. The central nucleus develops into the egg cell, while the two nuclei on either side
form the two synergid cells. The nuclei on the side opposite the micropyle within the embryo
sac are also enclosed by membranes, forming the antipodal cells. The two central nuclei form
the polar nuclei. At this stage, the embryo sac represents the mature female gametophyte.
Q: The functional megaspore in angiosperms (Magnoliophyta) is called _______.
ANS: Embryo sac
Q: The ________ in angiosperms (Magnoliophya) is called the embryo sac.
ANS: Functional megaspore.
Q: The functional megaspore in _________________ is called the embryo sac.
ANS: Angiosperms (Magnoliophyta).
Q: The functional (effective) megaspore represents the __________________.
ANS: Immature female gametophyte.
Q: Justify or Explain: The funiculus is curved downward in a mature ovule.
ANS: The funiculus curves downward to position the micropyle close to the funiculus,
although this relative position can vary.

RamadhanSci 79
Q: What’s the function of micropyle? )‫(وزاري‬
ANS: It allows the pollen tube to enter the embryo sac in order to perform double
fertilization.
Q: What’s the location of polar nuclei? )‫(وزاري‬
ANS: Center of embryo sac.
1- Egg cell (of flowering plants)
2- Synergid Cells
3- Antipodal Cells
ANS:
1- At the micropylar end of the embryo sac, in the center of three cells grouped there
(surrounded by two synergid cells [one on each side]).
2- At the micropylar end of the embryo sac, flanking the egg cell (one on the right and one
on the left).
3- At the end of the embryo sac opposite to the micropyle.
Pollination (Q/ Define: Pollination):
Pollination can be defined as the transport of pollen from the anther to the stigma of the same
plant or another plant. As a result of this transport, fertilization takes place, so pollination is one
of the essential processes that lead to seed production.
There are two types of pollination (Q/ List only: Type of pollination. Or a blank Q format):
1- Self pollination
2- Cross pollination
Self pollination (Q/ Define: Self-pollination ‫)وزاري‬:
This occurs through the transfer of pollen from the anther of a flower to the stigma of the same
flower, or to the stigma of a different flower on the same plant.
This type of pollination occurs in many kinds of plants, such as wheat, barley, rice, cotton,
beans, peas, and orange trees (or citrus trees in general).
Q: Give one example for each of the following: Plant performs self-pollination.

RamadhanSci 80
ANS: Any of the following is considered correct: Wheat, barley, rice, cotton, beans, peas, and
orange trees (or citrus trees in general).
Possible harder Qs is to give you one blank:
Self-pollination occurs in many kinds of plants, such as wheat, _________, rice, cotton, beans,
peas, and orange trees (or citrus trees in general).
ANS: Barley.
Cross pollination:
This type of pollination occurs through the transfer of pollen from the anther of one flower to
the stigma of a flower on another plant of the same kind, and sometimes even to other varieties
within the same species.
Cross-pollination occurs in many plants and is considered more important than self-pollination
because it produces larger fruits, in greater quantities, and with faster growth compared to
those resulting from self-pollination.
That’s why farmers are advised to keep beehives on or near their farms, to ensure cross-
pollination and, as a result, obtain larger quantities of high-quality produce.
Bees are among the most important and helpful insects in pollination. Some economists
estimate that pollination by bees contributes a huge economic value, averaging over 200 billion
dollars per year globally. There are also many other pollinating insects, such as wasps, beetles,
butterflies, and others.
Some vertebrates also contribute to pollination, such as birds and other animals.
In addition, wind and water play important roles in the transfer of pollen and thus in the
pollination process.
Humans can also perform pollination manually, for example, in date palm trees.
Q: Define: Cross pollination )‫(وزاري‬
ANS: This type of pollination occurs through the transfer of pollen from the anther of one
flower to the stigma of a flower on another plant of the same kind, and sometimes even to
other varieties within the same species. Cross-pollination occurs in many plants.
Q: Justify or Explain: Cross pollination is considered more important than self-pollination.
)‫(وزاري‬
ANS: Because it produces larger fruits, in greater quantities, and with faster growth compared
to those resulting from self-pollination.

RamadhanSci 81
Q: Justify or Explain: Farmers are advised to keep beehives on or near their farms. )‫(وزاري‬
ANS: To ensure cross-pollination and, as a result, obtain larger quantities of high-quality
produce.
1- An insect other than bees contributes to cross pollination
2- An insect with huge economic value, averaging over 200 billion dollars per year globally.
3- Vertebrate contributes to cross pollination
4- Natural phenomenon contributes to cross pollination
5- A plant that humans can help cross-pollinate.
6- A vertebrate helps to cross-pollinate the date palm trees.
ANS:
1- Beetles (or butterflies, or wasps)
2- Bees.
3- Birds and other animals (including humans)
4- Wind and water
5- Date palm trees
6- Humans
Q: Justify or Explain: Bees are considered economically valuable.
ANS: Because bees help in cross-pollination, which leads to large quantities of high-quality
produce, some economists estimate that bee pollination contributes over 200 billion dollars
per year globally.
Q: Some economists estimate that pollination by bees contributes a huge economic value,
averaging over ___________ dollars per year globally.
ANS: 200 billion.
Q: Compare: Self-pollination and cross-pollination )‫(وزاري‬
ANS:
Self-pollination Cross-pollination
Occurs through the transfer of pollen from
the anther of a flower to the stigma of the
the anther of one flower to the stigma of a

RamadhanSci 82
same flower, or to the stigma of a different
flower on the same plant.
flower on another plant of the same kind,
and sometimes even to other varieties within
the same species.
Occurs in many kinds of plants, such as
wheat, barley, rice, cotton, beans, peas, and
Occurs in many plants.
Fruits and seeds formed are smaller in size Fruits and seeds formed are larger in size.
The fruits and seeds formed are fewer in
quantity and grow more slowly.
The fruits and seeds formed are greater in
quantity and grow more quickly.
Q: What’s the function of cross-fertilization? )‫(وزاري‬
ANS: The fruits and seeds produced are larger in size, greater in quantity, and grow more
quickly.
Q: Justify or Explain: Fertilization in date palm trees is cross-fertilization. )‫(وزاري‬
ANS: Because date palm trees are dioecious (unisexual), meaning male and female flowers
are on separate plants. Therefore, cross-fertilization is necessary, and it occurs with the help
of humans and the wind.
Development of pollen tube:
After landing on the stigma, the pollen grain grows a narrow structure called the pollen tube.
Usually, each pollen grain produces one pollen tube.
The pollen tube grows and penetrates the stigma and style until it reaches the ovule, which
contains the egg cell. Although many pollen tubes may form, only one reaches the egg.
As the pollen tube grows, the generative cell undergoes one division (mitosis) to produce two
sperm cells.
Thus, the pollen tube contains a tube cell and two sperm cells, and at this stage, it represents
the mature male gametophyte, ready for fertilization.
Q: The pollen tube contains ___________ and ___________. )‫(وزاري‬
ANS: A tube cell; Two sperm cells.

RamadhanSci 83
Q: Describe the changes that occur in a pollen grain from the moment it lands on the stigma
until fertilization. )‫(وزاري‬
Or
Q: What changes occur in the pollen grain after it lands on the stigma. )‫(وزاري‬
Or
Q: How is the pollen tube formed? )‫(وزاري‬
ANS: After landing on the stigma, the pollen grain grows a narrow structure called the pollen
tube. Usually, each pollen grain produces one pollen tube. The pollen tube grows and
penetrates the stigma and style until it reaches the ovule, which contains the egg cell.
Although many pollen tubes may form, only one reaches the egg. As the pollen tube grows,
the generative cell undergoes one division (mitosis) to produce two sperm cells. Thus, the
pollen tube contains a tube cell and two sperm cells, and at this stage, it represents the
mature male gametophyte, ready for fertilization.
Q: What changes occur during the growth and maturation of the pollen tube? )‫(وزاري‬
Or
Q: Explain the process of pollen tube formation and development. )‫(وزاري‬
ANS:
The pollen tube grows and penetrates the stigma and style until it reaches the ovule, which
contains the egg cell. Although many pollen tubes may form, only one reaches the egg. As the
pollen tube grows, the generative cell undergoes one division (mitosis) to produce two sperm
cells. Thus, the pollen tube contains a tube cell and two sperm cells, and at this stage, it
represents the mature male gametophyte, ready for fertilization.
Q: Each pollen grain produces _____ pollen tube(s).
ANS: One.
Q: Although many pollen tubes may form, only ______ reaches the egg.
ANS: One.
1- Pollen tube
2- Sperm cells (of flowering plant)
3- Mature male gametophyte
ANS:
1- Haploid (n)
2- Haploid (n)

RamadhanSci 84
3- Haploid (n)
Q: What’s the origin of (or what is responsible for) pollen tube? )‫(وزاري‬
ANS: One of the germination pores of the pollen grain.
Q: What’s the function of pollen tube? )‫(وزاري‬
ANS: It transports the sperm cells from the pollen grain to the embryo sac to enable
fertilization.
Q: What’s the origin of (or what is responsible for) the two sperm cells (in flowering plants)?
)‫(وزاري‬
ANS: Generative cell.
Fertilization and Embryo development:
When the pollen tube reaches the ovule, it penetrates the micropyle, enters the nucellus, and
then moves into the embryo sac, where it releases its contents.
One of the sperm cells fuses with the egg cell to form a zygote with a diploid (2n) number of
chromosomes.
The second sperm cell fuses with the two polar nuclei to form the endosperm nucleus, which
has a triploid (3n) chromosomal set.
The fusion of one sperm with the egg nucleus and the other with the two polar nuclei is called
double fertilization, a unique feature of flowering plants.
After fertilization is completed, the three antipodal cells, the two synergid cells, and the tube
cell degenerate.
The zygote begins normal mitotic divisions, followed by growth and differentiation to form the
embryo.
The endosperm nucleus also undergoes multiple divisions to form the endosperm tissue, which
stores nutrients to support the embryo during its growth stages.
Q: What’s the function of micropyle? )‫(وزاري‬
ANS: It allows the pollen tube to enter the embryo sac in order to perform double
fertilization.

RamadhanSci 85
1- Endosperm nucleus )‫(وزاري‬
2- Endosperm tissue
3- Zygote of flowering plants
ANS:
1- Triploid (3n)
2- Triploid (3n)
3- Diploid (2n)
Q: Define: Double fertilization )‫(وزاري‬
ANS: One of the sperm cells fuses with the egg cell to form a zygote with a diploid (2n)
number of chromosomes. The second sperm cell fuses with the two polar nuclei to form the
endosperm nucleus, which has a triploid (3n) chromosomal set. The fusion of one sperm with
the egg nucleus and the other with the two polar nuclei is called double fertilization, a unique
feature of flowering plant.
Q: Justify or Explain: Endosperm nucleus is a triploid (3n) nucleus. )‫(وزاري‬
ANS: Because it is the result of the fusion of one sperm cell (n) with two polar nuclei (2n),
forming a triploid (3n) nucleus during double fertilization.
Q: Give an example of a triploid nucleus. )‫(وزاري‬
ANS: Endosperm nucleus.
Q: What’s the location and function of polar nuclei? )‫(وزاري‬
ANS:
Location → Center of embryo sac
Function → Fuse with one sperm cell to form the endosperm nucleus (3n).
Q: What is the origin of (or what is responsible for) endosperm? )‫(وزاري‬
ANS: The fusion of one sperm cell with two polar nuclei.
Q: Describe the events that occur in the ovule following double fertilization. )‫مهم‬ ‫(وزاري‬
ANS: After fertilization is completed, the three antipodal cells, the two synergid cells, and the
tube cell degenerate. The zygote begins normal mitotic divisions, followed by growth and
differentiation to form the embryo. The endosperm nucleus also undergoes multiple divisions
to form the endosperm tissue, which stores nutrients to support the embryo during its
growth stages.

RamadhanSci 86
Q: Give an example of: a unique feature of flowering plants.
ANS: Double fertilization.
Q: What’s the origin of (or what’s responsible for) endosperm tissue?
ANS: Endosperm nucleus (undergoes multiple divisions to form the endosperm tissue).
Q: What is the significance (or importance or function) of the endosperm tissue (or simply
‘the endosperm’)? )‫(وزاري‬
ANS: Stores nutrients to support the embryo during its growth stages.
Q: What is the location of endosperm? )‫(وزاري‬
ANS: In the seed.
We can summarize the growth stages in dicotyledons embryos as follows:
1- Zygote stage → At this stage, double fertilization takes place, producing the zygote and
the endosperm.
2- Proembryo stage → At this stage, the pro-embryo is multicellular, and its basal (lower)
part is impaired or non-functional.
3- Globular stage → At this stage, the embryo is shaped like a small ball.
4- Heart stage → At this stage, the embryo takes on a heart shape, and the cotyledons
begin to appear.
5- Torpedo stage → At this stage, the embryo takes on a torpedo-like shape (closely
resembling a cylindrical form), and the two cotyledons are clearly formed.
6- Mature embryo stage → The embryo becomes mature and begins to grow and
differentiate into a true embryo. It consists of the shaft (‫الجنيني‬ ‫)المحور‬ which is composed
of pre-leaf (‫رويشة‬, the early or young shoot), pre-root (‫جذير‬, the early or young root), and
split stem (‫فلقي‬ ‫)سويق‬ which carries the cotyledons (two in dicotyledons and one in
monocotyledons).
NOTE1: The English terms used in the book (e.g. "shaft", "pre-leaf", "split stem") are
not standard in botanical terminology. The widely accepted scientific terms are as
follows:
‫الجنيني‬ ‫المحور‬ = Embryonic axis
‫رويشة‬ = Plumule
‫جذير‬ = Radicle
‫فلقي‬ ‫سويق‬ = Hypocotyl

RamadhanSci 87
NOTE2: The terms I gave appear only in the book’s drawings, so I wouldn’t be
surprised if they show up in exam questions. That’s why I really want you to be
familiar with all these terms, I’m very serious about it.
NOTE3: In one of the drawings, the plumule (‫)الرويشة‬ is labeled as “‫جنينية‬ ‫ورقة‬,” which
translates to “embryonic leaf.” Just add that to your dictionary! ☺
NOTE4: In another drawing, the plumule is labeled as “young shoot.”
NOTE: The embryonic axis (the shaft) = Pre-leaf (plumule) + Pre-root (radicle) + Split stem
(hypocotyl).
NOTE: All the structures (plumule, radicle, and hypocotyl) are embryonic, meaning they
originate from the zygote, so they all have a diploid (2n) chromosome set.
Q: what are the chromosome sets for each:
1- Pre-leaf = ‫رويشة‬ = plumule → 2n. )‫(وزاري‬
2- Pre-root = ‫جذير‬ = radicle → 2n.
3- Split stem = ‫فلقي‬ ‫سويق‬ = Hypocotyl → 2n.
4- Shaft (of plant embryo) = ‫الجنيني‬ ‫المحور‬ = Embryonic axis → 2n.
Q: The shaft consists of _______, _______, and _______.
ANS: Pre-leaf; Pre-root; Split stem.
Q: The ________ consists of pre-leaf, pre-root, and split stem.
ANS: Shaft (embryonic axis).
Q: What are the growth stages in dicotyledons embryos? )‫(وزاري‬
Or
Q: What are the embryonic formation stages in dicotyledons?
ANS:
the endosperm.

RamadhanSci 88
begin to appear.
monocotyledons).
★ It is also possible to have shorter Qs:
- Explain the first 3 stages of embryo growth in dicotyledons.
- Explain the last 3 stages of embryo growth in dicotyledons.
- Explain the torpedo stage of embryo growth in dicotyledons (or any other stage, and possibly
in the form of a definition question).
Q: In the ________ stage of dicotyledon embryo growth, the embryo is shaped like a small ball.
ANS: Globular stage.
Q: In the ________ stage of dicotyledon embryo growth, the embryo is shaped like a torpedo.
ANS: Torpedo.
Q: What do the following sentences indicate: Embryo’s basal (lower) part is impaired or non-
functional.
ANS: Proembryo stage → At this stage, the pro-embryo is multicellular, and its basal (lower) part
is impaired or non-functional.
Q: What is the function of the split stem (‫الفلقي‬ ‫?)السويق‬
ANS: It carries the cotyledons (two in dicotyledons and one in monocotyledons).
Q: What is the function of the shaft (‫الجنيني‬ ‫?)المحور‬
ANS: It forms the true embryo and is composed of the pre-leaf (‫)رويشة‬, pre-root (‫)جذير‬, and the
split stem (‫فلقي‬ ‫)سويق‬.

RamadhanSci 89
Q: List only: The parts that make up the shaft (‫الجنيني‬ ‫)المحور‬ in the mature embryo?
ANS
1- Pre-leaf (‫)رويشة‬
2- Pre-root (‫)جذير‬
3- Split stem (‫فلقي‬ ‫)سويق‬
Q: Draw with labelling: Embryo formation in flowering plants.
Or
Q: Draw with labelling: Embryo formation in a dicotyledon
ANS:
The numbers in the image:
1 → Zygote stage
2 → Proembryo stage
3 → Globular stage
4 → Heart stage
5 → Torpedo stage
6 → Mature embryo stage
★ So, they can ask you to draw just one stage, or two or more, instead of the entire diagram.
Seed formation:
The formation of the seed starts directly after fertilization. The endosperm cell divides to form
the endosperm tissue, and the covering of the egg transforms into the seed coat, which is
called the testa (pl.: testae).

RamadhanSci 90
At the mature stage, the seed is formed from the embryo and a seed coat, as seen in most
dicotyledonous plants such as broad beans, green beans, and others.
However, there are plants like wheat, castor (‫خروع‬ aka castor bean, or castor oil plant) and corn
whose embryos do not use the endosperm until the seed is planted and begins to absorb water.
Thus, mature seeds formed in this way consist of the embryo, a seed coat (which may consist of
one or more layers), and sometimes the endosperm.
Q: The formation of the seed starts directly after __________.
ANS: Fertilization.
Q: What’s the origin of (or what’s responsible for) the seed? )‫(وزاري‬
ANS: The ovule after double fertilization.
Q: Give an example for each:
1- A seed that lacks endosperm )‫(وزاري‬
2- A seed that uses (contains) endosperm
3- Monocotyledonous seed
4- Dicotyledonous seed
5- Dicotyledonous seed that retains endosperm. (Advanced-level question)
ANS:
1- Broad beans, and green beans.
2- Wheat, castor, and corn.
3- Wheat, and corn.
4- Broad beans, green beans, and castor beans.
NOTE: Castor retains endosperm, unlike most dicots, it's an exception!
5- Castor beans.
Q: What’s the origin of (or what’s responsible for) the testa? )‫(وزاري‬
ANS: Covering of the egg (transforms into the seed coat, which is called the testa).
Q: What’s the location and function of endosperm? )‫(وزاري‬
ANS:
Location → in the seed.
Function → Stores nutrients to support the embryo during its growth stages.

RamadhanSci 91
Q: Justify or Explain: Some seeds like wheat and castor consist of the embryo, the protective
seed coat, and sometimes the endosperm. )‫(وزاري‬
ANS: Because such seeds do not use the endosperm until they are planted and begin
absorbing water.
Q: Draw with labelling: Seed structure in monocotyledon plants
ANS:

RamadhanSci 92
Q: Draw with labelling: Seed structure in dicotyledon plants
ANS:
Fruit formation:
The formation of a fruit begins with the growth and expansion of the ovary wall. This process is
accompanied by the development of the seed inside the ovary.
Fertilization acts as a trigger that stimulates the expansion of the ovary. In some cases, this
expansion may also involve other parts of the flower, such as the receptacle (as in apples) or
the flower coverings (as in berries). Fruits that develop from these additional parts are known
as false fruits.
A large quantity of food is required to develop the ovary into a fruit.
Nutrients such as glucose and amino acids are rapidly transported to the ovary wall through
the vascular tissues, which connect the parts of the flower to the stem.
These food materials are converted and stored as insoluble nutrient reserves, such as complex
sugars (like starch), proteins, and oils.
When the sugar content is high in fruits, it gives them a sweet taste. This is the case with fruits
such as grapes, dates, and bananas.

RamadhanSci 93
Sugar may be converted into starch at the maturity stage, as seen in crops like corn, grains, and
rice (and wheat is also mentioned in the Arabic source).
Oils can accumulate in large quantities in certain fruits, such as olives.
In other types of fruits, water may be stored instead, especially in juicy fruits (‫العصيرية‬ ‫)الثمار‬ and
fleshy (succulent) fruits (‫اللحمية‬ ‫)الثمار‬, such as watermelon, melon, and tomatoes.
On the other hand, some types of fruits have very low water content when mature, such as
walnuts, Hazelnuts, and almonds.
These kinds of changes in the fruit are often accompanied by changes in pigment.
For example, chlorophyll disappears and is replaced by carotene as some fruits mature, such as
in tomatoes.
In other cases, purple anthocyanin pigments may accumulate, as seen in grapes (black grapes)
and pears.
Pollen grains have two main roles. First, they produce the male reproductive cells that fertilize
the eggs through a process called double fertilization, which results in the formation of the
seed. Second, they stimulate the production of specific hormones that regulate the maturation
of the ovary and its transformation into a fruit.
Therefore, this process can sometimes be replaced by sprinkling certain hormones over the
ovary of some flowers. These plant hormones stimulate the ovary to mature and develop into
fruit, but these fruits do not contain seeds (they are seedless). This process is called artificial
parthenocarpy, and the resulting fruits are known as artificial parthenocarpic fruits.
However, there are some kinds of fruits that naturally have no seeds, and these are called
natural parthenocarpic fruits. Examples include pineapples, navel oranges (‫سرة‬ ‫أبو‬ ‫)برتقال‬, and
some types of grapes. It is believed that the ovaries of these flowers contain a high level of
hormones, which causes this seedless development.
Q: Pollen grains have two main roles, explain them. )‫(وزاري‬
Or
Q: What’s the function (or significance, or importance) of the pollen grain?
Or
Q: What role does the pollen grain play in the transformation of the ovary into a fruit? )‫(وزاري‬
Or
Q: What is the role of a mature pollen grain?
)‫الناضجة؟‬ ‫اللقاح‬ ‫حبوب‬ ‫دور‬ ‫ما‬ :‫الصيغة‬ ‫بهذه‬ ‫اجة‬ ‫بالعربي‬ ،‫مهم‬ ‫(وزاري‬
ANS: Pollen grains have two main roles. First, they produce the male reproductive cells that
fertilize the eggs through a process called double fertilization, which results in the formation
of the seed. Second, they stimulate the production of specific hormones that regulate the
maturation of the ovary and its transformation into a fruit.
Q: What changes will occur in the ovary of a flower after the pollen grain falls on its stigma
until the formation of the fruit? )‫(وزاري‬
ANS: After the pollen grain falls on the stigma, it forms a pollen tube that stimulates the
production of specific hormones. These hormones regulate the maturation of the ovary and

RamadhanSci 94
its transformation into a fruit. This process is supported by the rapid transport of nutrients,
such as glucose, amino acids, and proteins, to the ovary wall through the vascular tissues,
which connect the flower parts to the stem.
1- Natural parthenocarpic fruit (or natural parthenocarpy) → Pineapples, navel oranges
(‫سرة‬ ‫أبو‬ ‫)برتقال‬, and some types of grapes. )‫(وزاري‬
2- A fruit that is naturally seedless → Pineapples, navel oranges (‫سرة‬ ‫أبو‬ ‫)برتقال‬, and some
types of grapes. (‫)مشابه‬
3- A non-natural process that produces seedless fruits → Artificial parthenocarpy
4- Juicy fruit → Watermelon, melon, and tomatoes.
5- Fleshy (succulent) fruit → Watermelon, melon, and tomatoes.
6- A fruit where water is stored → Watermelon, melon, and tomatoes.
7- A fruit in which the receptacle contributes to its formation → Apple. )‫(وزاري‬
8- Fruits in which the flower coverings contribute to their formation → Berries. )‫(وزاري‬
9- Fruits that contain anthocyanin → Grapes and pears )‫(وزاري‬
10- Fruits that have low water content when mature (or Dry fruits, or Hard fruits) →
Walnuts, Hazelnuts, and almonds.
11- Fruits that have high sugar content (or fruits with sweet taste) → Grapes, dates, and
bananas.
12- False fruits → Apples and berries )‫(مشابه‬
13- Fruits in which oil accumulates → Olives.
14- A fruit that contains carotene → Tomato.
15- A fruit in which chlorophyll disappears and is replaced by another pigment (or a fruit
that changes pigment) → Tomato.
16- Fruits that contain starch at maturity → Corn, grains, and rice (and wheat is also
mentioned in the Arabic source).
17- Fruits that convert sugar into a more complex molecule at maturity → Corn, grains,
and rice (and wheat is also mentioned in the Arabic source).
Q: A ________________ is required to develop the ovary into a fruit.
ANS: Large quantity of food.
Q: What’s the origin of navel oranges? )‫(وزاري‬
ANS: From flower ovaries that naturally contain high levels of hormones (natural
parthenocarpic fruits).

RamadhanSci 95
★ The same applies if the question is about pineapples, ‘some types of grapes,’ or even
‘natural seedless fruits.’
Q: Justify or Explain: Pineapples produce seedless fruits. )‫(وزاري‬
Or
Q: Justify or Explain: Pineapples are natural parthenocarpic fruits. )‫(مشابه‬
ANS: It is believed that the ovaries of pineapple flowers contain high levels of hormones,
which lead to seedless fruit development without fertilization.
★ The same applies if the question is about navel oranges, ‘some types of grapes,’ or even
asking you to justify that natural seedless fruits (natural parthenocarpic fruits) exist.
Q: What are the characteristics or features for each of the following: Walnut fruits )‫(وزاري‬
ANS: They have very low water content when mature and reach a high level of dryness.
★ The same applies if the question is about hazelnuts, almonds, or even asking you to justify
that some fruits are hard and dry.
Q: What’s the origin of (or what is responsible for) each of the following:
1- The fruit → Ovary wall (or ‘ovary’). )‫(وزاري‬
2- The hardness of walnut fruits → Very low water content when mature and reach a
high level of dryness. )‫(وزاري‬
3- The hardness of almond fruits (or hazelnut fruits) → Very low water content when
mature and reach a high level of dryness. )‫(مشابه‬
4- The harness of some fruits → Very low water content when mature and reach a high
level of dryness. )‫(مشابه‬
5- Black color in grapes → Purple anthocyanin pigment. )‫(وزاري‬
NOTE: You might wonder, “If anthocyanin is responsible for purple or black coloration
in fruits, why does the book mention pears, which usually appear yellowish or
whitish?”
The reason is that some varieties of pears have a reddish tint in their skin, especially
around areas exposed to sunlight. These red pigments are due to anthocyanin
accumulation. In fact, red pears can resemble apples in appearance.
6- The reddish coloration in the skin of certain types of pears → The accumulation of
anthocyanin pigment in the skin. )‫(مشابه‬
7- Orange/yellow tomatoes → The disappearance of chlorophyll pigment and its
replacement with carotene.
NOTE: I didn’t mention red tomatoes here because carotene is a yellowish/orangish
pigment, as seen in carrots, not red. The red color in tomatoes is actually due to
lycopene, not carotene. However, since the textbook doesn’t distinguish clearly

RamadhanSci 96
between these pigments, they might still assess carotene as the pigment responsible
for the red color in tomatoes, even though that’s not technically accurate. Also, there
are tomato varieties that appear purple or black due to the accumulation of
anthocyanin, and there's no reason this couldn't show up in an assessment.
Additionally, some green tomatoes retain their chlorophyll and do not replace it with
carotenoids, which is another possible point that might be tested.
8- Artificial parthenocarpic fruits → Sprinkling certain hormones over the ovary of some
flowers. )‫(مهم‬
9- Natural parthenocarpic fruits → The ovaries of these flowers contain high levels of
hormones, which lead to seedless fruit development without fertilization. )‫(مهم‬
Q: What is the result of sprinkling the ovary of some flowers with hormones? )‫(وزاري‬
ANS: These plant hormones stimulate the ovary to mature and develop into fruit, but these
fruits do not contain seeds (they are seedless). This process is called artificial parthenocarpy,
and the resulting fruits are known as artificial parthenocarpic fruits.
Q: The process of sprinkling the ovary of some flowers with hormones to stimulate fruit
development is called __________, and the resulting fruits are known as __________.
ANS: Artificial parthenocarpy; Artificial parthenocarpic fruits.
Fruit structure:
Q: Define: Fruit.
A fruit can be defined as a mature ovary along with its contents and coverings. Seeds are
formed within the fruit, and the fruit itself is typically composed of three layers:
- Exocarp: This is the outer layer of the fruit, commonly referred to as the skin or cover
(or peel).
- Mesocarp: This is the middle layer of the fruit, commonly referred to as the flesh.
- Endocarp: This is the innermost layer, sometimes called the pith, and it directly
surrounds the seed.
These layers vary in their growth rate and thickness across different types of plants.
Q: List only: The layers of the fruit.
ANS:
1- Exocarp aka Skin, Cover, or Peel
2- Mesocarp aka Flesh
3- Endocarp aka Pith

RamadhanSci 97
Q: List and Explain the layers of the fruit.
ANS:
- Exocarp: This is the outer layer of the fruit, commonly referred to as the skin or cover
(or peel).
- Mesocarp: This is the middle layer of the fruit, commonly referred to as the flesh.
- Endocarp: This is the innermost layer, sometimes called the pith, and it directly
surrounds the seed.
These layers vary in their growth rate and thickness across different types of plants.
Q: The fruit layers vary in their growth rate and thickness across ___________.
ANS: Different types of plants.
Q: The fruit layers vary in their __________ and ________ across different types of plants.
ANS: Growth rate; Thickness.
Q: What’s the location for each of the following:
1- Exocarp → Outer layer of the fruit
2- Mesocarp → Middle layer of the fruit
3- Endocarp → Innermost layer of the fruit
Q: _________ is commonly referred to as the skin or cover.
ANS: Exocarp.
Q: _________ is commonly referred to as the flesh
ANS: Mesocarp.
Q: ______ is commonly referred to as the pith.
ANS: Endocarp.

RamadhanSci 98
Q: Draw with labelling: Fruit structure.
ANS:
Fruit types:
Q: List only: Fruit types.
ANS:
1- Simple fruits
2- Aggregate fruits
3- Compound fruits
1- Simple fruits (Q/ Define simple fruits ‫)وزاري‬:
These fruits are the product of a single flower with either one carpel or multiple fused carpels,
as in the case of broad beans, tomato, cucumber, orange, and apricot.
2- Aggregate fruits (Q/ Define aggregate fruits ‫)وزاري‬:
Exocarp

RamadhanSci 99
These fruits are formed from many separate carpels of a single flower. The individual fruitlets
are connected to a single receptacle, as seen in blackberries.
3- Compound fruits (Q/ Define compound fruits. Or Q/ Define Multiple fruits ‫)مهم‬:
They can also be called multiple fruits and are formed from a group of flowers. Each flower
forms a fruit, and they remain connected to each other at maturity, as in the case of pineapple.
1- Compound fruits (multiple fruits) )‫(وزاري‬
2- Aggregate fruits
3- Simple fruit
ANS:
1- Pineapple.
2- Blackberries
3- Broad beans, tomato, cucumber, orange, and apricot.
NOTE: Tomatoes and cucumbers are actually fruits, not vegetables, because they develop
from the flower and contain seeds. However, in everyday life, they’re often called vegetables
because of how we use them in cooking.
Vegetables, on the other hand, usually come from other parts of the plant such as the roots
(like carrots), stems (like celery), or leaves (like spinach).
Q: Tomatoes and cucumbers are _____ fruits.
ANS: Simple.
Dispersal of fruits and seeds: )‫مهم‬ ‫(وزاري‬
A large number of fruits and seeds contain special structures or features that help them
disperse easily into their environment or into similar environments. This dispersal can occur
through various agents such as wind, birds, animals, humans, and water. The structure of the
seed and the way the fruit opens also play important roles in the dispersal process.

RamadhanSci 100
Wind carries seeds and fruits away from the mother plant, as seen in the seeds of grasses,
weeds, and desert plants. These seeds are often very light or have special adaptations like
hairy, umbrella-shaped structures that help them float in the air, as in winged fruits (samaras).
An example mentioned in the Arabic book is ‫البردي‬ ‫نبات‬ (papyrus, also known as paper reed or
Nile grass).
Animals also help disperse seeds and fruits. Some seeds have prickles or hooks that stick to the
fur or skin of animals, allowing them to be carried over long distances away from the parent
plant.
Many aquatic plants rely on water currents or waves to disperse their seeds and fruits, ensuring
the survival of the species. Usually, the seeds and fruits of these plants are lightweight or have
coverings with air-filled spaces (air cavities) that help them float on the water’s surface, as seen
in coconuts.
1- Fruits that float on water → Coconuts
2- Fruits that have coverings with air-filled spaces (air cavities) → Coconuts.
3- Seeds that have hairy, umbrella-shaped structures → winged fruits (samaras), and ‫نبات‬
‫البردي‬ (papyrus, also known as paper reed or Nile grass). )‫مهم‬ ‫(وزاري‬
4- Seeds that float in the air → winged fruits (samaras), and ‫البردي‬ ‫نبات‬ (papyrus, also
known as paper reed or Nile grass).
5- A fruit that floats in the air (or seed of a fruit that floats in the air) → Winged fruit
(samaras)
6- A sedge that float in the air (or seed of a fruit that floats in the air) → Papyrus (paper
reed, or Nile grass).
7- Seeds and fruits carried away from the mother plant by the wind → Seeds of grasses,
weeds, and desert plants. These seeds are often very light or have special adaptations
like hairy, umbrella-shaped structures that help them float in the air, as in winged fruits
(samaras), and ‫البردي‬ ‫نبات‬ (papyrus, also known as paper reed or Nile grass).
8- Seeds and fruits that are dispersed with the help of animals → Seeds that have prickles
or hooks which stick to the skin or fur of animals, allowing them to be carried over long
distances.
9- Plants that rely on water currents or waves to disperse their seeds and fruits → Aquatic
plants. Their seeds and fruits are usually lightweight or have air-filled cavities that allow
them to float on water. Example: coconut.
10- A light seed → - Wind-dispersed light seeds: Seeds of papyrus, grasses, and weeds and
winged fruits are very light and often have structures that help them float in the air.
- Water-dispersed light seeds: are also lightweight (or have air cavities), which allows
them to float on water. Example: Coconut seeds.

RamadhanSci 101
Q: List the factors or agents that contribute to the dispersal of fruits and seeds.
ANS:
1- Wind
2- Water
3- Animals (like birds and humans)
4- The structure of the seed
5- The way the fruit opens
Q: What is responsible for each of the following:
1- Dispersal in seeds of grasses, weeds, desert plants, papyrus (Nile grass), winged fruits
(samaras), or seeds with light weight and hairy, umbrella-shaped structures→ Wind.
2- Dispersal in seeds that have prickles or hooks OR Seeds that stick to fur or skin →
Animals.
3- Dispersal in Coconuts, aquatic plants, or seeds that are lightweight or have coverings
with air-filled spaces (air cavities) → Water currents or waves.
Q: Justify or Explain: Wind carries seeds and fruits away from the mother plant, as seen in the
seeds of grasses, weeds, and desert plants.
ANS: Because these seeds are often very light or have special adaptations like hairy, umbrella-
shaped structures that help them float in the air, as in winged fruits (samaras), and ‫البردي‬ ‫نبات‬
(papyrus, also known as paper reed or Nile grass).
Q: Justify or Explain: Animals also help disperse seeds and fruits.
ANS: Because these seeds have prickles or hooks that stick to the fur or skin of animals, allowing
them to be carried over long distances away from the parent plant.
Q: Justify or Explain: Water currents or waves disperse many aquatic plants seeds and fruits.
ANS: Because seeds and fruits of these plants are lightweight or have coverings with air-filled
spaces (air cavities) that help them float on the water’s surface, as seen in coconuts.
★ You might get a long question asking you to explain the dispersal of fruits and seeds in detail,
covering all methods. Alternatively, you could be asked shorter questions focusing on specific
parts, like explaining dispersal by wind or water, and so on.

RamadhanSci 102
Vegetative propagation aka Vegetative reproduction:
It is a common type of asexual reproduction in many advanced plants and ferns. These plants
can undergo vegetative propagation through various structures such as stolons, which are stems
that grow along the surface of the ground, as well as rhizomes, tubers, corms, and bulbs. All of
these are vegetative parts of the plant and are not involved in sexual reproduction, but they
serve to propagate the plant asexually.
There are generally two types of vegetative propagation:
First: Natural vegetative propagation
This occurs in several ways:
1- Propagation by stolons ➔ One of the types of vegetative propagation as is seen in
strawberries. A horizontal stem, known as a stolon, can extend up to a meter along the
surface of the ground. At specific points called nodes (or knots) on the stolon, new
vertical shoots (young plants) begin to grow. From each node, new roots grow
downward into the soil, while new stems and leaves grow upward. This new plant can
naturally separate from the mother plant when the stolon connecting them dies, or it
can be manually detached and replanted elsewhere.
2- Propagation by rhizomes ➔ This is a vegetative propagation way which most of the
weeds (the Arabic book says ‫المعمرة‬ ‫الحشائش‬, best translated as perennial weeds,
meaning plants that live for more than two years, i.e., ‫)معمر‬ and ferns reproduce by.
It happens through the formation of terrestrial stems that extend beneath the soil
surface, called rhizomes. Adventitious roots grow from these stems into the soil, while
green parts (stems and leaves) emerge from buds above the ground.
Terrestrial stems (which are perennial stems – ‫معمرة‬ ‫)سيقان‬ extend rapidly through the
growth of their apical buds (also called terminal buds – ‫النهائية‬ ‫)البراعم‬, covering new
ground quickly. If these rhizomes happen to break into pieces during soil tilling (e.g.
plowing), each piece can grow into a new plant. Garden grass and iris are examples of
this type of vegetative propagation.
3- Propagation by tubers ➔ Tubers are enlarged, food-storing terrestrial stems that grow
underground. Tubers contain several small depressions called "eyes." Each eye holds one
or more buds known as axillary buds. Typically, a single plant produces a group of
tubers, each capable of developing new shoots from its buds in the following growing
season (often spring), such as in the case of the potato.
4- Propagation by bulbs and corms ➔ This type of vegetative propagation occurs in many
herbaceous plants through the formation of bulbs. A bulb is a single, rounded (globular),
large bud. It has a short disc-shaped stem at the base, from which fleshy and scaly
leaves (‫ولحمية‬ ‫حرشفية‬ ‫أوراق‬) grow upward, and adventitious roots (‫عرضية‬ ‫جذور‬) grow
downward.

RamadhanSci 103
Buds emerge from the axils of the fleshy leaves, and these buds are similar to the
mother bulb. Each bud may either separate to form a new independent bulb or remain
attached to the original bulb. This form of vegetative propagation is seen in onion, garlic,
narcissus, and lily.
Corms are also a method of vegetative propagation, and they are morphologically similar
to bulbs, but with one major difference: the main swollen part of a corm is stem tissue,
while in bulbs, it's primarily scaly leaf and fleshy leaf tissue. The leaves of corms are
usually thinner and smaller than those of bulbs.
Corms reproduce by forming buds at the axils of scaly leaves on the stem, and these
buds can develop into new corms that eventually separate from the mother plant.
This type of propagation is seen in gladiolus, earth apple (Jerusalem artichoke ‫بالعراقي‬
‫نسميه‬
‫الگاع‬ ‫تفاح‬
‫او‬
‫االلمازة‬
‫بالطرشي‬ ‫ناكله‬ ‫وغالبا‬ ), turmeric, and German turnip (turnip cabbage,
or Kohlrabi – ‫)الكلم‬.
Second: Artificial vegetative propagation
Many plants lose their ability to produce viable seeds, as seen in bananas, grapes, and some
types of oranges. In other cases, such as the date palm, reproduction by seed takes a very long
time. Additionally, it may be difficult to determine the exact species, variety, or even the sex of
the plant when grown from seed. Because of these challenges, farmers often resort to
vegetative propagation as a more reliable and efficient method.
Some plants cannot reproduce vegetatively on their own and need stimulation using plant
hormones such as indole acetic acid, indole butyric acid, and naphthalene acetic acid.
The methods of artificial vegetative propagation are as follows:
1. By offsets ➔ Offsets are large buds that frequently form at the base of the stem of the
mother plant, near its connection with the soil. From these offsets, adventitious roots
develop and extend into the soil. Once the offset has grown sufficiently, it can be
separated from the mother plant and transplanted to another location, where it
continues to grow as an independent plant. Examples of plants propagated in this way
include date palm and banana.
2. By layering ➔ It is a method of vegetative propagation in which the branch or shoot
remains attached to the mother plant and is buried under the soil.
Some plants can form adventitious roots if they touch the earth and are covered with
soil. Man has utilized this characteristic in propagating some plants, in that a twig is bent
while still connected to the mother plant, and part of it — or its apical bud aka terminal
bud (‫طرفي‬ ‫)برعم‬ — is covered with some quantity of soil. This process is known as
layering.
After burying the branch under the soil for a period, which may last six weeks or more,
adventitious roots begin to form on the buried part of the plant. Once the roots have
developed, the branch is cut off from the original plant, and it becomes an independent

RamadhanSci 104
plant.
Examples of plants that can be propagated using this method include grape, lemon,
orange, bougainvillea ( ‫الورد‬
‫الجهنمي‬ ), and others.
Aerial layering: If the branch is too hard to bend down to the soil, aerial layering can be
used. This is done by enclosing the target part of the branch with a soil-filled pot or
wrapping (like moss or moist soil wrapped in plastic). After a period (usually about 6
weeks), roots form within the enclosure, and the rooted branch can then be cut and
replanted elsewhere.
3. Propagation by grafts ➔ Grafting is the process of attaching a part of one plant to
another plant. This method is used to reproduce plants that have desired characteristics.
In an experiment, if a bud-bearing part of a plant, like from an orange tree, is taken and
placed onto another plant with similar features, like a lemon tree, the orange bud will
grow and produce flowers and fruits as if it were growing on its original tree.
The part that contains the buds is called the scion, while the plant it’s attached to is
called the stock.
★ Meaning, the orange bud will grow on the lemon tree, and it will still produce
oranges, not lemons.
Here, the orange is the scion, and the lemon is the stock.
The fruit type always comes from the scion, not the stock.
This technique is super useful when the stock plant is more disease-resistant or better
adapted to the environment than the scion.
There are two main types of grafting: budding and cleft grafting.
a. Budding grafting: a bud is taken from a plant with desirable traits and inserted
into a T-shaped incision in the bark of the stock plant. The sides of the T-cut are
gently lifted, and the bud is placed inside so that its tissues come into contact
with the cambium layer of the stock. The flaps of bark are then closed over the
bud and tied securely in place to ensure proper union and growth.
b. Cleft grafting: Cleft grafting is a method of vegetative propagation where the
stem of the stock plant is cut horizontally near the soil surface. A vertical split
(cleft) is then made in the center of this cut.
A scion branch, typically containing two or three buds, is taken and its base is
sharpened or beveled on both sides, similar to the shape of a wedge or pencil.
The prepared scion is carefully inserted into the cleft, ensuring that the cambium
tissues of both the scion and the stock match up on at least one side to promote
proper growth and union.
The grafted area is then tied securely, and in some cases, covered with grafting
wax to protect it from drying out or infection.
If the stem of the stock is large, more than one scion may be inserted into
different parts of the split to ensure successful grafting.

RamadhanSci 105
It is important to note that grafting is generally only successful when the scion
and the stock share similar characteristics, meaning they must belong to the
same botanical family or group. For example, orange cannot be grafted onto
peach, as they are from different families. However, orange can be grafted onto
lemon, and peach can be grafted onto plum, since they are more closely related.
NOTE: In the Arabic version of the book, they mention ‫إجاص‬ ‫مع‬ ‫خوخ‬ — meaning
peach with pear, not plum. But you should be familiar with both, because the
exam questions can be annoyingly inconsistent.
Important Qs:
Q: List only: Ways of natural vegetative propagation.
ANS:
1. Propagation by stolon
2. Propagation by rhizomes
3. Propagation by tubers
4. Propagation by bulbs
5. Propagation by corms
Q: List only: Ways of artificial vegetative propagation.
ANS:
1. Propagation by offsets
2. Propagation by layering
a. Aerial layering
3. Propagation by grafts
a. Buffing grafting
b. Cleft grafting
★ You might get the question in different ways: asking you to list and explain one or two, or to
list them and give one example for each (this is how it’s usually asked in ‫)الوزاري‬. And this is how
you should answer the example part of the question:

RamadhanSci 106
- Propagation by stolon → Strawberries.
- Propagation by rhizomes → Garden grass, iris, most of the weeds (perennial weeds), and
ferns.
- Propagation by tubers → Potato.
- Propagation by bulbs → Onion, garlic, narcissus, lily, and many herbaceous plants.
- Propagation by corms → Gladiolus, earth apple, turmeric, and German turnip.
- Propagation by offsets → Banana and date palm.
- Propagation by layering → Grape, lemon, orange, and bougainvillea.
- Propagation by aerial layering → Commonly used for hard-to-bend branches, like grape,
lemon, orange, bougainvillea.
- Propagation by grafts → Orange grafted onto lemon/Peach grafted onto plum (or pear)
- Propagation by budding grafts → Orange bud inserted into lemon stock/Peach bud
inserted into plum (or pear) stock
- Propagation by cleft grafting → Orange scion inserted into lemon stock stem/Peach
scion inserted into plum (or pear) stock stem
Q: Justify or Explain: Farmers often resort to artificial vegetative propagation. (‫مهم‬ ‫)وزاري‬
ANS: Because many plants lose their ability to produce viable seeds, as seen in bananas, grapes,
and some types of oranges. In other cases, such as the date palm, reproduction by seed takes a
very long time. Additionally, it may be difficult to determine the exact species, variety, or even
the sex of the plant when grown from seed. Because of these challenges, farmers often resort
to vegetative propagation as a more reliable and efficient method. Some plants cannot
reproduce vegetatively on their own and need stimulation using plant hormones such as indole
acetic acid, indole butyric acid, and naphthalene acetic acid.
Q: Justify or Explain: Farmers often stimulate vegetative plant growth using plant hormones.
ANS: Because Some plants cannot reproduce vegetatively on their own and need stimulation
using plant hormones such as indole acetic acid, indole butyric acid, and naphthalene acetic
acid.
Q: List the hormones used in vegetative propagation. )‫مهم‬ ‫(وزاري‬
ANS: Indole acetic acid, indole butyric acid, and naphthalene acetic acid.
Q: Compare: Bulb and corm. )‫جدا‬ ‫مهم‬ ‫متكرر‬ ‫(وزاري‬
ANS:
Bulb Corm
A single, rounded (globular), large bud. It has
a short disc-shaped stem at the base
Morphologically similar to bulbs, but with
one major difference: the main swollen part

RamadhanSci 107
of a corm is stem tissue, while in bulbs, it's
primarily scaly leaf and fleshy leaf tissue.
Fleshy and scaly leaves are larger in size. The leaves of corms are usually thinner and
smaller than those of bulbs.
Buds emerge from the axils of the fleshy
leaves
Buds emerge from the axils of the scaly
leaves
The bigger part is the scaly leaf and fleshy
leaf tissue
The bigger part is the stem tissue
Examples: Onion, garlic, narcissus, and lily. Examples: Gladiolus, earth apple, turmeric,
and German turnip.
Q: What’s the origin of (or what’s responsible for) corms? )‫(وزاري‬
ANS: From the axils of the scaly leaves, it separates from the mother corm to develop into
new corms.
Q: Define: Grafting (or propagation by grafts) )‫(وزاري‬
ANS: Grafting is the process of attaching a part of one plant to another plant. This method is
used to reproduce plants that have desired characteristics. In an experiment, if a bud-bearing
part of a plant, like from an orange tree, is taken and placed onto another plant with similar
features, like a lemon tree, the orange bud will grow and produce flowers and fruits as if it
were growing on its original tree. The part that contains the buds is called the scion, while the
plant it’s attached to is called the stock. There are two main types of grafting: budding and
cleft grafting.
Q: Define: Budding grafting.
ANS: a bud is taken from a plant with desirable traits and inserted into a T-shaped incision in the
bark of the stock plant. The sides of the T-cut are gently lifted, and the bud is placed inside so
that its tissues come into contact with the cambium layer of the stock. The flaps of bark are
then closed over the bud and tied securely in place to ensure proper union and growth.
Q: Define: Cleft grafting.
Or
Q: Explain or Write down what you know about cleft grafting.
ANS: Cleft grafting is a method of vegetative propagation where the stem of the stock plant is
cut horizontally near the soil surface. A vertical split (cleft) is then made in the center of this cut.
A scion branch, typically containing two or three buds, is taken and its base is sharpened or
beveled on both sides, similar to the shape of a wedge or pencil. The prepared scion is carefully
inserted into the cleft, ensuring that the cambium tissues of both the scion and the stock match
up on at least one side to promote proper growth and union. The grafted area is then tied
securely, and in some cases, covered with grafting wax to protect it from drying out or infection.

RamadhanSci 108
If the stem of the stock is large, more than one scion may be inserted into different parts of the
split to ensure successful grafting. It is important to note that grafting is generally only
successful when the scion and the stock share similar characteristics, meaning they must belong
to the same botanical family or group. For example, orange cannot be grafted onto peach, as
they are from different families. However, orange can be grafted onto lemon, and peach can be
grafted onto plum (or pears), since they are more closely related.
Q: Justify or Explain: Pear grafted onto peach )‫(وزاري‬
ANS: To adapt and acclimate plants to different and new environments. For example, pear
does not grow well in sandy soil, but it can be successfully cultivated in such soil by grafting it
onto peach rootstock, which thrives in that type of soil. This is also possible because they
share similar characteristics (i.e., they belong to the same plant family).
Q: Justify or Explain: Farmers propagate navel orange only through grafting. )‫(وزاري‬
ANS: Because it is a plant that does not produce seeds, farmers resort to propagating it
through grafting.
NOTE: The same applies to other seedless fruits like pineapples, and seedless grapes.
Q: Propagation by grafts is used to reproduce plants with ________.
ANS: Desired properties.
Q: Propagation by ________ is used to reproduce plants with desired properties.
ANS: Grafts.
Q: What is the type of vegetative reproduction or propagation (or what’s the type of asexual
reproduction) for each of the following: )‫جدا‬ ‫ومهم‬ ‫وزاريات‬ ‫كلهن‬ ‫(تقريبا‬
1. Navel orange → Grafting (artificial vegetative propagation)
2. Grape → Propagation by layering (artificial vegetative propagation)
3. Some types of seedless grapes → Grafting (artificial vegetative propagation)
4. Seedless pineapple → Grafting (artificial vegetative propagation)
5. Onion → Propagation by bulbs (natural vegetative propagation)
6. Garlic → Propagation by bulbs (natural vegetative propagation)
7. Lily → Propagation by bulbs (natural vegetative propagation)
8. Narcissus → Propagation by bulbs (natural vegetative propagation)
9. Gladiolus → Propagation by corms (natural vegetative propagation)
10. Earth apple → Propagation by corms (natural vegetative propagation)
11. Turmeric → Propagation by corms (natural vegetative propagation)

RamadhanSci 109
12. German turnip (aka turnip cabbage, or Kohlrabi) → Propagation by corms (natural
vegetative propagation)
13. Strawberries → Propagation by stolons (natural vegetative propagation)
14. Potato → Propagation by tubers (natural vegetative propagation)
15. Bougainvillea → Propagation by layering (artificial vegetative propagation)
16. Date palm → Propagation by offsets (artificial vegetative propagation)
17. Banana → Propagation by offsets (artificial vegetative propagation)
18. Hard-to-bend branches → Propagation by aerial layering (artificial vegetative
propagation)
19. Most of the weeds (perennial weeds) → Propagation by rhizomes (natural vegetative
propagation)
20. Ferns (or most ferns) → Propagation by rhizomes (natural vegetative propagation)
21. Many herbaceous plants → Propagation by bulbs (natural vegetative propagation)
22. Iris → Propagation by rhizomes (natural vegetative propagation)
23. Garden grass → Propagation by rhizomes (natural vegetative propagation)
24. Citrus fruits → Propagation by grafts (artificial vegetative propagation)
25. Peach → Propagation by grafts (artificial vegetative propagation)
26. Plum (or pear) → Propagation by grafts (artificial vegetative propagation)
27. Lemon → Propagation by layering and grafts (artificial vegetative propagation) ‫اجة‬ ‫هيچ‬
‫بالوزاري‬ ‫الجواب‬
★ The same should be applied to oranges.
28. Orange → Propagation by layering and grafts (artificial vegetative propagation)
29. Orange bud inserted into lemon stock → Propagation by budding grafts (artificial
30. Peach bud inserted into plum (or pear) stock → Propagation by budding grafts (artificial
31. Orange scion inserted into lemon stock stem → Propagation by cleft grafting (artificial
32. Peach scion inserted into plum (or pear) stock stem → Propagation by cleft grafting
(artificial vegetative propagation)

RamadhanSci 110
Q: Define: Bulb )‫(وزاري‬
ANS: A bulb is a single, rounded (globular), large bud. It has a short disc-shaped stem at the
base, from which fleshy and scaly leaves grow upward, and adventitious roots grow downward.
Buds emerge from the axils of the fleshy leaves, and these buds are similar to the mother bulb.
Each bud may either separate to form a new independent bulb or remain attached to the
original bulb. This form of vegetative propagation is seen in onion, garlic, narcissus, and lily.
Q: What is the origin of (or what is responsible for) each of the following: Bulb ‫لسؤال‬ ‫(مشابه‬
)‫الكورمة‬
ANS: Emerges from the axils of the fleshy leaves, and it may either separates from the mother
plant to form a new independent bulb or remains attached to the original bulb.
Q: Define: Tubers )‫(وزاري‬
ANS: Tubers are enlarged, food-storing terrestrial stems that grow underground. Tubers contain
several small depressions called "eyes." Each eye holds one or more buds known as axillary
buds. Typically, a single plant produces a group of tubers, each capable of developing new
shoots from its buds in the following growing season (often spring), such as in the case of the
potato.
Q: Justify or Explain: Tubers are considered stems, not roots. )‫مهم‬ ‫(وزاري‬
ANS: Because tubers contain buds and small depressions called "eyes," which are
characteristics of stems, not roots.
Q: What is the location of the buds in tubers? )‫مهم‬ ‫(وزاري‬
ANS: The buds are located in the depressions on the surface of the tuber, known as ‘eyes.’
Q: What is the location and function of eyes?
ANS:
Location → The eyes are located on the surface of the tuber, in small depressions. Each eye
contains one or more buds.
Function → Each eye contains one or more buds. The eyes give rise to new shoots (buds), which
grow into stems and leaves. This allows the tuber to reproduce vegetatively and form a new
plant.

RamadhanSci 111
Q: Define: Eyes
ANS: Eyes are small depressions on the surface of a tuber that contain one or more axillary
buds. These buds can sprout and give rise to new shoots, allowing the tuber to grow into a new
plant.
Q: Define: Propagation by layering )‫مهم‬ ‫(وزاري‬
ANS: It is a method of vegetative propagation in which the branch or shoot remains attached to
the mother plant and is buried under the soil. Some plants can form adventitious roots if they
touch the earth and are covered with soil. Man has utilized this characteristic in propagating
some plants, in that a twig is bent while still connected to the mother plant, and part of it — or
its apical bud aka terminal bud (‫طرفي‬ ‫)برعم‬ — is covered with some quantity of soil. This process
is known as layering. After burying the branch under the soil for a period, which may last six
weeks or more, adventitious roots begin to form on the buried part of the plant. Once the roots
have developed, the branch is cut off from the original plant, and it becomes an independent
plant. Examples of plants that can be propagated using this method include grape, lemon,
orange, bougainvillea (‫الجهنمي‬ ‫)الورد‬, and others.
Aerial layering: If the branch is too hard to bend down to the soil, aerial layering can be used.
This is done by enclosing the target part of the branch with a soil-filled pot or wrapping (like
moss or moist soil wrapped in plastic). After a period (usually about 6 weeks), roots form within
the enclosure, and the rooted branch can then be cut and replanted elsewhere.
Q: Define: Aerial layering
ANS: If the branch is too hard to bend down to the soil, aerial layering can be used. This is done
by enclosing the target part of the branch with a soil-filled pot or wrapping (like moss or moist
soil wrapped in plastic). After a period (usually about 6 weeks), roots form within the enclosure,
and the rooted branch can then be cut and replanted elsewhere.
Q: Vegetative parts of the plant are not involved in ________ reproduction.
ANS: Sexual.
Q: Vegetative propagation is a common type of asexual reproduction in many _________ and
______.
ANS: Advanced plants; Ferns.
Q: Justify or Explain: Vegetative propagation is a type of asexual reproduction.
ANS: Because it relies on vegetative parts of the plant, such as stems, roots, or leaves, which
are not involved in sexual reproduction and do not require flowers or seeds.

RamadhanSci 112
NOTE: All vegetative parts used in asexual (vegetative) propagation, like bulbs, corms, stolons,
tubers, and grafts, are diploid (2n) because they come from somatic tissue, not gametes.
1. Stem → 2n
2. Root → 2n
3. Leaves → 2n
4. Stolons → 2n
5. Tubers → 2n
6. Rhizomes → 2n
7. Buds → 2n
8. Bulbs → 2n
9. Corms → 2n
10. Grafts → 2n
11. Scion → 2n
12. Stock → 2n
13. Offsets → 2n
14. Mature fruit (the fruit wall tissue itself) → 2n
15. Seed → This depends on which part of the seed
a. Seed coat → 2n
b. The embryo → 2n
c. Endosperm → 3n
16. Nodes → 2n
17. Internodes → 2n
18. Adventitious roots → 2n
19. Terminal (Apical) Bud → 2n
20. Axillary (Lateral) Bud → 2n
21. Vegetable → Remember that vegetable parts are stems, leaves, roots, tubers, bulbs, etc.
→ So, 2n.
Q: What do the following sentences indicate: A horizontal stem that can extend up to a meter
along the surface of the ground.
ANS: Stolon.
Q: Give an example of: A horizontal stem that can extend up to a meter along the surface of the
ground.
ANS: Stolon.

RamadhanSci 113
Q: What is the origin of (or what is responsible for):
1. New vertical shoots from stolon
2. New young plants from stolon
3. New stems and leaves in stolon
4. New roots in stolon
ANS:
1. They emerge from nodes (knots) on the stolon.
2. They emerge from nodes (knots) on the stolon.
3. They grow upward from the nodes (knots)
4. They grow downward from the nodes (knots) into the soil.
Q: What is responsible for separating the new plant from the mother plant in stolon-based
propagation (e.g., in strawberries)?
ANS: Either the stolon dies naturally, or the new plant is manually detached and replanted
elsewhere.
The Importance of Vegetative Propagation in Plants
Vegetative propagation is used in plants for several purposes (Q: What are the purposes of
vegetative propagation? Or Q: What is the importance of vegetative propagation? Or Q: What
are the benefits of vegetative propagation? ‫مهم‬ ‫)وزاري‬:
1. To propagate plants that do not produce seeds.
2. To propagate hybrid plants without change, since their seeds do not produce plants
identical to the parents.
3. To propagate plants whose seeds have low germination rates.
4. To increase the propagation speed and speed up fruiting.
5. To adapt the plants to new conditions (or new environments). For example, roots of pear
trees do not grow well in sandy soil, but they can be grown in such soil successfully by
grafting them onto stocks of peach trees, whose roots thrive in this soil.

RamadhanSci 114
6. Preventing infection by certain parasites that attack the roots of specific plant types but
not others. For example, roots of the European grape are vulnerable to a type of
parasite that does not affect the roots of the American grape. If stocks of the American
grape are grafted with those of the European grape, the latter can grow without being
exposed to these parasites.
Q: Give an example for each of the following: Plants adapt to new environments (or new
conditions). )‫مهم‬ ‫(وزاري‬
ANS: Grafting roots of pear trees onto peach tree rootstock (since pear tree roots do not grow
well in sandy soil).
Q: What is the type of vegetative propagation (or asexual reproduction) for:
1. European grape
2. American grape
ANS: Grafting, the European grape is grafted onto the rootstock of the American grape to
protect it from parasites that attack European grape roots.
Q: Give an example of: Grafting plants to prevent infection by a type of parasite.
ANS: Grafting European grape onto the rootstock of American grape.
Plant tissue culture:

RamadhanSci 115
The plantation of plant tissues is regarded as one of the applications of vital techniques that
help in the reproduction of plants, and this represents artificial vegetative propagation.
Simply, it means the development of plant tissues and cells outside the plant body, in a
controlled environment or proper nutrient medium. As a result, plant buds are formed and, at
the appropriate time, they develop into mature plants.
The advantage of this tissue culture technique in plants is to obtain plants with desired traits,
such as salt resistance or tolerance to temperature changes. It is also used to overcome some
agricultural challenges, such as long life cycles, as in the case of the date palm, or the
unavailability of sufficient quantities of plant seedlings.
Tissue culture has become common worldwide and in Iraq. Some studies conducted at research
centers in Iraq have achieved notable success in this field, which could serve as a foundation for
the spread of this agricultural technique. This is especially important since tissue culture is
considered one of the main methods for propagating date palms, a crop that thrives in Iraq.
The tissue plantation for date trees can be summarized as follows (Q/ What are the steps [or
stages] of tissue culture [or tissue plantation] for date trees? ‫مهم‬ ‫)وزاري‬:
1. One of the offsets is separated from the mother date palm plant, preferably an actively
growing offset.
2. The apical growing part is extracted from the offset, and this requires a sterilized
medium to prevent contamination of the extracted tissue.
3. The apical growing part is partitioned (cut) into small pieces, which must contain active
living cells.
4. The living tissues are planted in special culture media that contain suitable nutrients.
The cultivation is carried out under sterile conditions around and within the tissue
cultures, while ensuring that temperature and humidity levels are appropriate.
5. They are transferred to a special glass container and cared for under good sterile
conditions until they reach the stage where they are ready to be planted in the natural
environment.
Q: Define: Plant tissue culture )‫جدا‬ ‫مهم‬ ‫(وزاري‬
Or
Q: Define: Plant tissue plantation
ANS: The plantation of plant tissues is regarded as one of the applications of vital techniques
that help in the reproduction of plants, and this represents artificial vegetative propagation.
Simply, it means the development of plant tissues and cells outside the plant body, in a
controlled environment or proper nutrient medium. As a result, plant buds are formed and, at
the appropriate time, they develop into mature plants. The advantage of this tissue culture
technique in plants is to obtain plants with desired traits, such as salt resistance or tolerance to
temperature changes. It is also used to overcome some agricultural challenges, such as long life
cycles, as in the case of the date palm, or the unavailability of sufficient quantities of plant
seedlings. Tissue culture has become common worldwide and in Iraq. Some studies conducted

RamadhanSci 116
at research centers in Iraq have achieved notable success in this field, which could serve as a
foundation for the spread of this agricultural technique. This is especially important since tissue
culture is considered one of the main methods for propagating date palms, a crop that thrives in
Iraq.
1. A plant that is commonly propagated by tissue culture. )‫(وزاري‬
2. A crop that thrives in Iraq
3. A country where research centers have achieved notable success in plant tissue culture.
4. A plant with a long life cycle
5. A plant for which tissue culture is used to overcome the challenge of a long life cycle.
6. A plant that benefits from tissue culture to overcome agricultural challenges.
ANS:
1. Date palms
2. Date palms
3. Iraq
4. Date palm
5. Date palm
6. Date palm
Q: Justify or Explain: Tissue culture is spreading in Iraq and worldwide.
ANS: Because some studies at research centers in Iraq have achieved notable success, which can
be the basis for spreading this agricultural technique. This is especially important since tissue
culture is considered one of the main methods for propagating date palms, a crop that thrives in
Iraq.
Q: Justify or Explain: Tissue culture especially important for date palms.
ANS: Because tissue culture is one of the main methods to propagate date palms, which thrive
in Iraq.
Q: What are the purposes of using tissue culture in plants? )‫جدا‬ ‫مهم‬ ‫(وزاري‬
Or
Q: What are the reasons for using tissue culture? )‫جدا‬ ‫مهم‬ ‫(وزاري‬
ANS: The advantage of this tissue culture technique in plants is to obtain plants with desired
traits, such as salt resistance or tolerance to temperature changes. It is also used to overcome
some agricultural challenges, such as long life cycles, as in the case of the date palm, or the
unavailability of sufficient quantities of plant seedlings.

RamadhanSci 117
Q: Justify or Explain: The extraction of the apical growing part in tissue culture requires highly
sterile conditions. )‫مهم‬ ‫(وزاري‬
ANS: To prevent contamination of the extracted tissue.
Reproduction in animals:
The members of the animal kingdom show major differences in their modes of reproduction.
Most animals reproduce sexually, but some reproduce both sexually and asexually. The basic
structure of the reproductive system in animals is generally similar, although differences in
reproductive habits and fertilization methods have led to many variations, especially among
vertebrates.
Q: The basic structure of the reproductive system in animals is generally ______.
ANS: Similar.
Q: Justify or Explain: Although animal reproductive systems are generally similar, many
variations exist in vertebrates.
ANS: Because differences in reproductive habits and fertilization methods cause structural and
functional changes, especially in vertebrates.
Reproduction in hydra:
Hydra belongs to the phylum Cnidaria and the class Hydrozoa. They are mostly sea-living
animals, but some live in fresh water. Hydra may live individually or in colonies. Its ideal life
cycle includes two stages: the asexual stage (Polyp) and the sexual stage (Medusa).
‫باالحمر‬ ‫وزارية‬ ‫فراغات‬
Note that freshwater Hydra does not have the sexual Medusa stage. Some types of Hydra
reproduce only sexually, without the asexual stage.
In general, Hydra can reproduce both asexually and sexually.
1. An animal that does not reproduce sexually
2. An animal that only reproduces asexually
3. An animal that only reproduces sexually
4. An animal that reproduces both sexually and asexually.

RamadhanSci 118
ANS:
1. Freshwater hydra
2. Freshwater hydra
3. Humans
4. Hydra
Asexual reproduction (Q/ Explain the asexual reproduction in hydra Or Q/ Explain budding in
hydra ‫مهم‬ ‫)وزاري‬:
Hydra reproduces asexually by budding, and this form of reproduction occurs when food is
available. Typically, at the beginning of the last third of the body, a small protrusion called a bud
forms. This bud contains a cavity that is a continuation of the main body cavity of the parent
(mother) hydra.
The bud grows and elongates, and once it reaches a suitable size, small projections begin to
form at its distal end, which later develop into tentacles, followed by the formation of the
mouth. Over the course of several days, the bud continues to grow until it becomes a fully
formed small hydra attached to the parent.
After a short period, a constriction forms at the base of the bud, where it connects to the
parent's body. Eventually, the bud detaches from the mother, its base closes, and the opening
left on the mother’s body also seals, allowing the new hydra to begin an independent life.
One hydra may produce multiple buds, each developing into a new individual.
Hydra also reproduces asexually by another method known as fragmentation and regeneration.
It has been found that when a hydra is cut into several pieces, most of the pieces are capable of
regenerating into complete, small-sized hydras.
Q: Draw with labelling: Asexual stage (polyp) of hydra
ANS:
Mouth Tentacle
Neck
Basal disc
Gastrointestinal
cavity
Body layers
(ectoderm and
endoderm) with
mesoglea

RamadhanSci 119
Q: Draw with labelling: Sexual stage (medusa) of hydra
ANS:
Q: What is the type of asexual reproduction in hydra? )‫مهم‬ ‫(وزاري‬
ANS:
1. Budding
2. Fragmentation and regeneration
Q: Explain fragmentation and regeneration in hydra.
ANS: In addition to budding, Hydra also reproduces asexually by another method known as
fragmentation and regeneration. When a Hydra is cut into several pieces, most of them are
capable of regenerating into complete, small-sized individuals.
Mouth
Tentacle
Gastrointestinal cavity
Mesoglea
Ectoderm
Body layers (ectoderm
and endoderm) with
mesoglea

RamadhanSci 120
Sexual reproduction:
Hydra is present in nature either Monoecious or Hermaphrodite so the animal has ovaries and
testes in the same individual. There are some kinds of hydra separated sex (Dioecious) so the
testes are in one animal and the ovaries in another animal.
NOTE: In animals like hydra, the terms monoecious and hermaphrodite usually mean the
same thing, both male and female organs are in one individual. So this sentence may be
repetitive. In plants, however, the two terms have different meanings.
Hydra is stimulated to form ovaries and testes under certain conditions, such as changes in
temperature and increased concentration of carbon dioxide in the water, especially during the
autumn season.
Hydra’s gonads (reproductive organs) appear as protrusions covered by the outer layer of the
body wall. The testes usually take a conical shape and are located in the upper half of the body,
while the ovaries appear as spherical structures situated in the lower half, close to the basal
disc.
The testes develop from interstitial cells located in the body wall. These are undifferentiated
cells capable of transforming into any cell type when needed. The interstitial cells produce
spermatogonia, which undergo a series of developmental stages to form sperm cells. These
sperm then accumulate in a swollen structure that opens to the outside, releasing the sperm
into the water, where they find their way to the egg.
The ovary is formed in the same way as the testis, as some interstitial cells differentiate to form
oogonia (egg precursors). The size of one of these oogonia, usually the central one, increases, as
it is nourished by surrounding degenerating cells. The oogonium undergoes several
developmental stages to become a large, mature ovum. Once the ovum is fully formed, the
epidermal layer (skin layer) surrounding it splits, and the ovum remains attached at the base of
the ovary until it meets the free-swimming sperm, at which point fertilization occurs and a
zygote is formed.
The fertilized egg (zygote) undergoes developmental stages while still attached to the mother’s
body. Later, it detaches after being enclosed by a protective shell that helps it withstand
unfavorable environmental conditions. In the spring, the zygote hatches into a young hydra.

RamadhanSci 121
Q: Draw with labelling: Sexual reproduction in hydra
ANS:
Usually, the questions will ask you to draw only one structure at a time:
- Draw with labelling: Ovary structure in hydra ‫وزاري‬
- Draw with labelling: Testes structure in hydra ‫وزاري‬
- Draw with labelling: Fertilization in hydra ‫مهم‬
- Draw with labelling: Embryo formation in hydra ‫جدا‬ ‫مهم‬ ‫وزاري‬
- Draw the young hydra hatching out
- Draw the male hydra
- Draw the female hydra
Q: Define: interstitial cells ‫مهم‬ ‫وزاري‬
ANS: Interstitial cells are undifferentiated cells capable of transforming into any cell type when
needed, located in the body wall of hydra.

RamadhanSci 122
Q: What is the location and function of interstitial cells ‫مهم‬ ‫وزاري‬
ANS:
Location → In body wall of hydra
Function → Undifferentiated cells capable of transforming into any cell type when needed.
Q: Explain the process of testes formation in Hydra? ‫مهم‬ ‫وزاري‬
Or
Q: Explain the process of sperm (or spermatogonia) formation in Hydra?
ANS: The testes usually take a conical shape and are located in the upper half of the body, and
appear as protrusions covered by the outer layer of the body wall. The testes develop from
interstitial cells located in the body wall. The interstitial cells produce spermatogonia, which
undergo a series of developmental stages to form sperm cells. These sperm then accumulate in
a swollen structure that opens to the outside, releasing the sperm into the water, where they
find their way to the egg.
Q: Explain the process of ovaries formation in Hydra? )‫(مشابه‬
Or
Explain the process of ova (or oogonia) formation in Hydra?
ANS: The ovaries appear as spherical structures situated in the lower half of the body, close to
the basal disc, and appear as protrusions covered by the outer layer of the body wall. The ovary
is formed in the same way as the testis, as some interstitial cells located in the body wall
differentiate to form oogonia (egg precursors). The size of one of these oogonia, usually the
central one, increases, as it is nourished by surrounding degenerating cells. The oogonium
undergoes several developmental stages to become a large, mature ovum. Once the ovum is
fully formed, the epidermal layer (skin layer) surrounding it splits, and the ovum remains
attached at the base of the ovary until it meets the free-swimming sperm, at which point
fertilization occurs and a zygote is formed.
Q: Explain the process of gonads (reproductive organs) formation in hydra?
ANS: The two Qs above combined.
Q: What is the origin of (or what is responsible for) each of the following:
1. Testes in hydra ‫مهم‬ ‫وزاري‬
2. Sperm in hydra ‫مهم‬ ‫وزاري‬
3. Spermatogonia in hydra ‫مهم‬ ‫وزاري‬
4. Ovaries in hydra ‫مهم‬ ‫وزاري‬
5. Ova (eggs) in hydra
6. Oogonia in hydra ‫مهم‬ ‫وزاري‬
ANS:
1. From interstitial cells located in the body wall

RamadhanSci 123
2. Produced by spermatogonia (which originate from interstitial cells) through sequential
developmental stages.
3. Originate from interstitial cells.
4. Interstitial cells in the body wall.
5. Produced from oogonia (which originate from interstitial cells) after undergoing
formation stages (nourished by surrounding degenerating cells and increased in size).
6. Derived from interstitial cells.
Q: What changes occur in the fertilized egg of the hydra until it becomes a young hydra? ‫وزاري‬
‫مهم‬
ANS: The fertilized egg (zygote) undergoes developmental stages while still attached to the
mother’s body. Later, it detaches after being enclosed by a protective shell that helps it
withstand unfavorable environmental conditions. In the spring, the zygote hatches into a young
hydra.
Q: Hydra is stimulated to form gonads under certain conditions, such as ____________. ‫وزاري‬
‫مهم‬
ANS: Changes in temperature and increased concentration of carbon dioxide in the water,
especially during the autumn season.
Q: What is responsible for each of the following: Stimulation of Hydra to form gonads. ‫مهم‬ ‫وزاري‬
ANS: Changes in temperature and increased concentration of carbon dioxide in the water,
especially during the autumn season.
Q: What happens to Hydra in:
1. Autumn season
2. Spring season
ANS:
1. Hydra is stimulated to form gonads (ovaries and testes) due to changes in temperature
and increased carbon dioxide concentration in water.
2. The fertilized egg (zygote) hatches and develops into a young hydra.
Q: What is the location for each of the following:
1. Testes in hydra
2. Ovaries in hydra
ANS:
1. Located in the upper half of the body, usually near the tentacles, and have a cone-like
shape.

RamadhanSci 124
2. Located in the lower half of the body, near the basal disc, and appear as spherical
structures.
Q: The testes in hydra have a _______ shape, while the ovaries in hydra have a ________ shape.
ANS: Conical; Spherical.
Reproduction in planaria:
Planaria belongs to the phylum Platyhelminthes (flatworms), which includes a wide variety of
worms. Their lengths range from as small as 1 millimeter to several meters, as seen in
tapeworms. Their flattened bodies can be thin, broad like a leaf, or long and ribbon-like.
Planaria reproduces both asexually and sexually.
Q: Planaria belongs to the phylum ____________.
ANS: Platyhelminthes (flatworms).
Q: The body of a flatworm can be broad like a __________ or long like a __________.
ANS: Leaf; Ribbon (or tape).
Q: Give an example of a flatworm that can reach several meters in length.
ANS: Tapeworm.
Q: Give an example of a flatworm that can be as small as 1 millimeter.
ANS: Planaria.
Q: Give an example of a flatworm with a ribbon-like body.
ANS: Tapeworm.
Q: Give an example of a flatworm with a flat, leaf-like body.

RamadhanSci 125
ANS: Planaria.
Asexual reproduction in planaria:
Planaria reproduces asexually through two main methods: fragmentation and regeneration,
and binary fission.
In fragmentation and regeneration, when the worm is cut into multiple pieces, each piece can
grow and regenerate into a new, complete worm. Laboratory experiments have shown that this
regeneration is an important model for experimental studies. For example, if a piece is cut from
the middle of the Planaria, it can regenerate both a new head and a new tail. Interestingly, the
fragment retains its original polarity, meaning the head always regenerates at the front end, and
the tail at the rear end. In binary fission, which is common in freshwater planaria, the animal
constricts behind the pharynx (throat). This constriction deepens gradually until the animal
splits into two individuals, and each individual regenerates the missing parts to become a
complete organism. This binary fission is a rapid method of reproduction and is usually adopted
when there is a decline in the population of planaria, as observed in experimental settings.
Q: What is the type of asexual reproduction in planaria? )‫مهم‬ ‫(وزاري‬
ANS:
1. Fragmentation and regeneration
2. Binary fission
Q: Justify or Explain: Planaria reproduces by binary fission. )‫مهم‬ ‫(وزاري‬
ANS: Because binary fission is a fast method of asexual reproduction that allows the planaria to
quickly increase its population, especially when there is a decrease in the number of individuals
in the environment.
Sexual reproduction in planaria:
Planaria is a hermaphrodite, meaning that a single individual possesses both male and female
reproductive organs. The male reproductive organs consist of numerous spherical testes, which
are connected to the vas deferens (sperm ducts). These ducts join at the penis, which opens
into a common chamber called the genital cloaca. At the base of the penis lies the seminal
vesicle, where sperm is stored after being produced in the testes and transported via the vas

RamadhanSci 126
deferens. The sperm remains in the seminal vesicle until needed.
The female reproductive organs include two ovaries, two long oviducts (egg tubes) connected
to multiple yolk glands, a uterus, and a vagina, both of which also open into the genital cloaca.
Eggs are formed in the ovaries, then pass through the oviducts to the uterus where fertilization
occurs, resulting in the formation of a cocoon.
During mating, sperm is transferred from one individual to another (between the two
copulating animals). The reproductive organs of planaria are specifically structured to prevent
self-fertilization, ensuring genetic diversity.
Q: Justify or Explain: Self-fertilization does not occur in planaria. )‫مهم‬ ‫(وزاري‬
ANS: Because the reproductive organs of planaria are specifically structured to prevent self-
fertilization, ensuring genetic diversity.
Q: What is the location and function of seminal vesicle in planaria? )‫مهم‬ ‫(وزاري‬
ANS:
Location → At the base of the penis.
Function → Stores the sperm after being produced in the testes. The sperm remains in the
seminal vesicle until needed.
Q: What is the type of sexual reproduction in planaria?
ANS: Cross-fertilization between hermaphrodites.

RamadhanSci 127
Q: Draw with labelling: Reproductive organs of planaria.
ANS:

RamadhanSci 128
Reproduction in Earthworm:
The earthworm belongs to the phylum Annelida (segmented worms), a large phylum that
includes around 9,000 species. The most familiar members are earthworms and freshwater
worms from the group Oligochaeta (few bristles or few pili), but the majority of the species
(about two-thirds) are marine worms (sea worms).
Earthworms reproduce sexually and are hermaphroditic, meaning that both male and female
reproductive organs are present in the same individual.
The male reproductive system of the earthworm consists of the following structures (Q/
Describe the male reproductive system of earthworm Or Q/ what are the components [or
structures] of the male reproductive system of earthworm ‫جدا‬ ‫مهم‬ ‫)وزاري‬:
- Two pairs of small testes (4 individual testes), located in segments 10 and 11.
- Two sperm funnels, each shaped like a funnel and situated close to each testis.
- A pair of vas deferens, which extend posteriorly and open externally on segment 15,
each through a separate male genital pore on the ventral surface.
- Each side's testes, sperm funnels, and vas deferens are enclosed by three seminal
vesicles, making a total of three pairs of seminal vesicles per individual.
Immature sperm (spermatocytes) are transported from the testes to the seminal vesicles,
where they mature. Then they pass through the sperm funnels, into the vas deferens, and
finally exit the body through the male genital pores on segment 15, especially during
copulation.
The female reproductive system consists of the following (Q/ Describe the female
reproductive system of earthworm Or Q/ What are the components [or structures] of the
female reproductive system of earthworm):
- A pair of small ovaries located in body segment 13.
- A pair of ciliated funnels (fimbriae) located near the ovaries in the same segment; each
extends into the following segment.
- A pair of oviducts, which continue into segment 14 and open separately on the ventral
surface through the female genital pores in segment 14.
- Two pairs of spermathecae (seminal receptacles) located in segments 9 and 10:
o The first pair opens into the groove between segments 9 and 10.
o The second pair opens into the groove between segments 10 and 11.
Intercourse in earthworm (Q/ Explain the intercourse [or copulation, or mating] in earthworm
‫)وزاري‬:
Copulation in earthworms usually occurs at night, especially during warm and humid weather
in spring and summer. After mating begins, each worm extends the front part of its body out of
the burrow so that the ventral surfaces of both worms are pressed together in opposite

RamadhanSci 129
directions. This positioning ensures that the clitellum (saddle) of each worm is aligned with the
openings of the spermathecae of the other worm. The two worms stick together with the help
of mucus secreted by the clitellum. Their bodies are coated in a slimy sheath extending from
segment 8 to just before the clitellum. During mating, both worms exchange sperm. The sperm
is released from the vas deferens openings located on the ventral side of segment 15 and moves
under the mucus sheath toward the clitellum of the other worm, entering its spermathecae.
This is known as cross-fertilization because each worm donates sperm to the other.
After separating, the clitellum of each worm begins to secrete a mucous ring that forms a tube-
like structure around it, called a cocoon. As the worm moves, the cocoon slides forward along
its body. When it reaches segment 14, where the oviduct openings are located, eggs are
released into the cocoon. As the cocoon continues to slide and reaches the openings of the
spermathecae, sperm are also released into it. This results in a cocoon that contains both eggs
and sperm. Eventually, the cocoon slips off the worm’s body entirely, and fertilization takes
place inside it. The cocoon is deposited in moist soil, where new individuals develop without
passing through a larval stage. After two to three weeks, the cocoon hatches, releasing young
worms that resemble adult earthworms.
Q: Compare: Male reproductive system and female reproductive system of the earthworm.
)‫مهم‬ ‫(وزاري‬
ANS:
Male reproductive system Female reproductive system
Two pairs of small testes (4 individual testes),
located in segments 10 and 11.
A pair of small ovaries located in body
segment 13.
Two sperm funnels, each shaped like a funnel
and situated close to each testis.
A pair of ciliated funnels (fimbriae) located
near the ovaries in the same segment; each
extends into the following segment.
A pair of vas deferens, which extend
posteriorly and open externally on segment
15, each through a separate male genital
pore on the ventral surface.
A pair of oviducts, which continue into
segment 14 and open separately on the
ventral surface through the female genital
pores in segment 14.
Each side's testes, sperm funnels, and vas
deferens are enclosed by three seminal
vesicles, making a total of three pairs of
seminal vesicles per individual.
Immature sperm (spermatocytes) are
transported from the testes to the seminal
vesicles, where they mature. Then they pass
through the sperm funnels, into the vas
deferens, and finally exit the body through
Two pairs of spermathecae (seminal
receptacles) located in segments 9 and 10:
- The first pair opens into the groove between
segments 9 and 10.
- The second pair opens into the groove
between segments 10 and 11.

RamadhanSci 130
the male genital pores on segment 15,
especially during copulation.
Q: Explain the processes that the earthworm performs after receiving the sperm from the other
worm. ‫مهم‬ ‫وزاري‬
ANS: After separating, the clitellum of each worm begins to secrete a mucous ring that forms a
tube-like structure around it, called a cocoon. As the worm moves, the cocoon slides forward
along its body. When it reaches segment 14, where the oviduct openings are located, eggs are
Q: What is the location and function of spermatheca (or seminal receptacle)? )‫مهم‬ ‫(وزاري‬
ANS:
Location → in segments 9 and 10.
Function → stores sperm received from another earthworm during copulation until it is needed
for fertilization.
Q: What is the location and function of seminal vesicles of earthworm? )‫مهم‬ ‫(وزاري‬
ANS:
Location → Covering the testes, sperm funnels, and vas deferens on each side.
Function → Store and mature the sperm produced by the testes before releasing it during
mating.
Q: Justify or Explain: Earthworms have spermathecae and seminal vesicles. )‫مهم‬ ‫(وزاري‬
ANS: Spermathecae store sperm received from another worm until fertilization occurs, while
seminal vesicles store the worm’s own sperm until it is fully mature.
Q: What do the following sentences indicate: A process in earthworms usually occurs at night,
especially during warm and humid weather in spring and summer.
ANS: Intercourse (or copulation, or mating).

RamadhanSci 131
Q: What is the origin of (or what is responsible for) cocoon? )‫مهم‬ ‫(وزاري‬
ANS: Clitellum (saddle).
Q: What is the function of cocoon? )‫مهم‬ ‫(وزاري‬
ANS: Collects sperm and eggs for fertilization in the earthworm.
It serves as a protective capsule where fertilized eggs develop. Inside the cocoon, fertilization
occurs and embryos develop into young worms, which later hatch without a larval stage.
Q: Mention a feature (or characteristic) of fertilization in the earthworm? )‫مهم‬ ‫(وزاري‬
ANS: Cross fertilization in a hermaphroditic worm.
Q: What is the function of clitellum (saddle)? )‫مهم‬ ‫(وزاري‬
ANS:
1. Forms the cocoon.
2. Secretes a mucous substance that helps the two worms stick together during mating.
Q: What is the location of the ovaries in earthworm? )‫مهم‬ ‫(وزاري‬
ANS: Body segment 13.
Q: The testes of earthworm are located in body segments ________, and the ovaries are located
in body segment _____. ‫جدا‬ ‫ومهم‬ ‫متكرر‬ ‫وزاري‬
ANS: 10 and 11; 13.
Q: The ovaries of earthworm are located in body segment _______, and vas deferens extend
until body segment _______. )‫مهم‬ ‫(وزاري‬
ANS: 13; 15.
Q: When does fertilization occur in the earthworm? )‫مهم‬ ‫(وزاري‬
ANS: When the cocoon slips off the body of the worm.

RamadhanSci 132
Q: Justify or Explain: Self-fertilization does not occur in the earthworm despite it being
hermaphroditic. )‫مهم‬ ‫(وزاري‬
ANS: Because the sperms and eggs do not mature at the same time, and to allow for acquiring
new genetic traits.
Reproduction in insects:
Insects exhibit a wide range of variations in their reproductive systems and reproductive
behaviors. This diversity stems from the enormous variety of insect species, as they represent
the most diverse group of animals, comprising nearly one million known species.
Insects are typically dioecious, meaning the sexes are separate, male and female. In most
species, females are larger than males. Other differences between the sexes include coloration,
the presence or absence of wings, and variations in the shape of antennae, legs, and other body
structures.
Q: Justify or Explain: Insects exhibit a wide range of variations in their reproductive systems and
reproductive behaviors.
ANS: This diversity stems from the enormous variety of insect species, as they represent the
most diverse group of animals, comprising nearly one million known species.
Q: Give an example of: The most diverse group of animals.
ANS: Insects.
Q: Give an example of: Group of animals comprising one million species.
ANS: Insects.
Q: Differences between sexes in insects include _________, the presence or absence of wings,
and variations in the shape of antennae, ________, and other body structures.
ANS: Coloration; Legs.
Reproductive organs in insects:
The reproductive organs in male and female insects are not distinguishable until the growth
stage, after embryonic development is complete. The reproductive system differs between
males and females across insect species.
In general, the insect reproductive organs are divided into two main parts:

RamadhanSci 133
1. Internal reproductive organs: These consist of a pair of gonads (testes or ovaries), a
group of associated ducts (or efferent ducts, but the book says ‘exported canals,’ which
does not make any sense), and several accessory structures such as glands, the
spermatheca (in females), and others.
2. External reproductive organs: These include the ovipositor in females, and the
copulatory apparatus in males.
Male reproductive system in insects:
The male reproductive system consists of the following parts:
1. Two testes, located either above or beside the digestive tract. In insects, each testis is
composed of a group of fine tubules called seminiferous tubules.
2. The seminiferous tubules open into a small duct on the same side, known as the vas
deferens. The anterior part of the vas deferens connects to the testis, while the
posterior part connects to the seminal vesicle, which is an expanded region of the vas
deferens that stores sperm.
3. The two vasa deferentia (this is the pl. form of vas deferens) unite to form the
ejaculatory duct, which extends into the penis. The penis opens at its tip through the
genital opening, through which sperm are released.
4. The accessory glands, located near the beginning of the ejaculatory duct, secrete a
mucous fluid that surrounds the sperm and forms a sac-like structure known as the
sperm sac (or spermatophore).
Female reproductive system in insects:
The female reproductive system consists of the following parts:
1. A pair of ovaries, each composed of several fine tubules called ovarioles. These ovarioles
do not contain lumens (cavities). Each ovariole contains developing oogonia and
oocytes, arranged in a chain-like structure, along with nurse cells that provide nutrition
to the developing oocytes, and other supporting (somatic) cells (or in addition to other
tissue cells).
2. Two lateral oviducts, each one connected to the posterior part of an ovary.
3. The two lateral oviducts merge to form the common oviduct (main oviduct).
4. The vagina, which is the posterior part of the female reproductive system. The common
oviduct opens into it.
5. The seminal receptacle (spermatheca) is a sac-like structure attached to the female
reproductive system in most insects. Some insects may have two or even three
spermathecae. The seminal receptacle is usually connected to a gland called the
spermathecal gland (gland of seminal receptacle), which secretes a fluid that helps
preserve the sperm while it is stored in the receptacle.

RamadhanSci 134
6. The spermatheca is attached to the dorsal wall of the vagina, and it receives sperm
during copulation, then later releases them to fertilize the eggs.
7. Accessory glands are a pair of glands that open into the vagina. The structure and
function of these glands vary among insect species. In some insects, such as
cockroaches, they are responsible for forming the egg case (ootheca, or ovisac). In bees,
they may be involved in defense, while in ants, they are used for trail marking.
Fertilization and reproduction in insects:
Fertilization occurs when two adult insects, a male and a female of the same species, come
together and mating takes place. During mating, the male and female genital openings align,
allowing the male to ejaculate sperm into the female's vagina. At the same time, the female
releases her mature eggs into the vagina, where they are fertilized by the sperm.
Female insects typically lay their fertilized eggs in environments suitable for the growth of the
offspring. They may deposit eggs in holes dug using the ovipositor, attach them to plant leaves,
or insert them into plant stems.
Insects that reproduce by laying eggs are called oviparous, and the process is known as ovipary.
However, some insects do not lay eggs. Instead, they give birth to larvae or nymphs, and are
referred to as viviparous. In some cases, the insect retains the fertilized eggs inside its body,
specifically in the common oviduct, until the embryos develop and the eggs hatch internally,
after which the young are released. This form of reproduction is called ovovivipary, and such
insects are referred to as ovoviviparous.
Q: What is the location and function of Accessory glands in male insects? )‫مهم‬ ‫(وزاري‬
ANS:
Location → Near the beginning of the ejaculatory duct.
Function → Secrete a mucous fluid that surrounds the sperm and forms a sac-like structure
known as the sperm sac (or spermatophore).
Q: What is the function of Accessory glands in female insects? )‫مهم‬ ‫(وزاري‬
ANS:
In cockroach (female) → form the egg case (ootheca, or ovisac).
In bees → involved in defense.
In ants → used for trail marking.
★ You can shorter Qs like: what is the function of Accessory glands in ants (or female ants) …
and so on.
Q: What is the function of Accessory glands in male and female cockroaches? )‫مهم‬ ‫(وزاري‬

RamadhanSci 135
ANS:
Male cockroach → Secrete a mucous fluid that surrounds the sperm and forms a sac-like
structure known as the sperm sac (or spermatophore).
Female cockroach → form the egg case (ootheca, or ovisac).
★ In questions, most of the time the sex is specified. But if it isn’t, you should write
down the general function for males (Secrete a mucous fluid that surrounds the sperm
and forms a sac-like structure known as the sperm sac [or spermatophore]) and the
specific function for females (i.e., cockroach = form the egg case [ootheca, or ovisac],
bees = involved in defense, Ants = used for trail marking).
And yeah, male bees and ants do exist, but:
- Male bees (drones) only mate and then die. Their accessory glands are involved in sperm
transfer (just write down the general function in male insect)
- Male ants are rare and seasonal. Their role is the same, sperm transfer only (just write
down the general function in male insect).
Q: What is the origin of the sting apparatus in the worker bee (Ar: ‫ما‬
‫منشأ‬
‫النحل‬ ‫عاملة‬ ‫في‬ ‫اللسع‬ ‫آلة‬ )?
ANS: Accessory glands.
Q: Justify or Explain: The presence of the seminal receptacle (spermatheca) in the female
reproductive system of insects. )‫جدا‬ ‫مهم‬ ‫(وزاري‬
ANS: Because it receives sperm during copulation, then later releases them to fertilize the
eggs. The seminal receptacle is usually connected to a gland called the spermathecal gland
(gland of seminal receptacle), which secretes a fluid that helps preserve the sperm while it is
stored in the receptacle.
Q: Justify or Explain: The function of the accessory glands varies in insects. )‫جدا‬ ‫مهم‬ ‫(وزاري‬
ANS: Because in some insects, the accessory glands are responsible for forming the egg case
(ootheca, or ovisac), as in female cockroaches. In other cases, they may be used for defense,
as in worker bees, or for marking trails, as in ants. In males, they secrete a mucous fluid that
surrounds the sperm and forms a sac-like structure called sperm sac (or spermatophore).
Q: Justify or Explain: Some insects are ovoviviparous. )‫جدا‬ ‫مهم‬ ‫(وزاري‬

RamadhanSci 136
ANS: Because these insects retain the fertilized eggs inside their body, specifically in the
common oviduct, until the embryos develop and the eggs hatch internally, after which the
young are released.
Q: What is the origin of (or what is responsible for): Ejaculatory duct of insects. ‫متكرر‬ ‫(وزاري‬
)‫جدا‬ ‫ومهم‬
ANS: The union of the two vasa deferentia.
Q: What is the origin of (or what is responsible for): Ovisac (egg case, or ootheca) in cockroach.
)‫جدا‬ ‫ومهم‬ ‫متكرر‬ ‫(وزاري‬
ANS: Accessory glands.
Q: What results from the activity of the accessory glands in the female cockroach? )‫(وزاري‬
ANS: It leads to the formation of the egg case (ootheca, or ovisac) in the cockroach.
Q: Define: Accessory glands )‫مهم‬ ‫وزاري‬ ‫(تعريف‬
ANS: A pair of glands in insects located near the beginning of the ejaculatory duct in males, and
open into the vagina in females. In males, they secrete a mucous fluid that surrounds the sperm
and forms a sac-like structure known as the sperm sac (or spermatophore). In females, the
function of these glands vary among insect species. in some insects, such as cockroaches, they
are responsible for forming the egg case (ootheca, or ovisac). In bees, they may be involved in
defense, while in ants, they are used for trail marking.
Q: Ovarioles in female insects contain _______, oocytes, and _________ in addition to other
tissue cells. )‫مهم‬ ‫وزاري‬ ‫(فراغ‬
ANS: Oogonia; Nurse cells.

RamadhanSci 137
Q: Draw with labelling: Male reproductive system in insect
ANS:
Q: Draw with labelling: Female reproductive system in insect
ANS:
Male
Female

RamadhanSci 138
Reproduction in frog:
The frog belongs to the class Amphibia within the phylum Vertebrata. It serves as an excellent
model that clearly demonstrates the body plan of tetrapods (four-limbed vertebrates). Frogs
reproduce sexually.
Q: What is the type of reproduction in frog?
ANS: Sexual reproduction
Q: Give an example of a tetrapod.
ANS: Frog. Other common examples include: humans, and bird.
Male reproductive system in frog:
The male reproductive system in the frog consists of the following:
- A pair of testes, each attached to the kidneys. Each testis is an elongated, oval (egg-
shaped) structure with a pale yellow color. It is connected to the inner body wall by a
membrane called the mesorchium.
- Near the anterior end of each testis, there are several finger-like projections known as
fat bodies, which serve as food reserves. The frog uses these fat bodies to support testis
development during the hibernation season (winter).
- The testes contain seminiferous tubules, which are responsible for the process of
spermatogenesis (the formation of sperm cells).
- The vasa efferentia are 10–12 small ducts and connect to the seminiferous tubules. The
vasa efferntia also connect to the kidney tubules.
- The vas deferens are two ducts that are shared with the kidney canals; for this reason,
they are called the urogenital ducts. These ducts carry both urine and sperm, and they
open into the cloaca. In some frogs, the posterior part of the vas deferens expands to
form a seminal vesicle, which serves as a storage site for sperm. Frogs do not have
external male copulatory organs.
Female reproductive system in frog (Q/ Explain [or write down what you know about] the
female reproductive system in frog ‫)وزاري‬:
The female reproductive system in the frog consists of the following structures:
- Two ovaries are located near the kidneys and are attached to the inner body wall by a
membrane called the mesovarium. Each ovary in the frog is an irregular, sac-like
structure, appearing as a multi-lobed (multi-lobed sac) with a gray to blackish color.
During the breeding season, both ovaries become greatly enlarged.
- Eggs are formed from germinal epithelial cells lining the ovary through the process of
oogenesis

RamadhanSci 139
- At the anterior end of each ovary are fat bodies, similar to those found in the male.
- The two oviducts in the frog are long, white, glandular tubes that are coiled and do not
connect directly to the ovaries. The anterior end of each oviduct forms a funnel-shaped
structure with a fringed (fimbriae) opening, whose cilia help move the eggs backward
into the oviduct. The lining of the oviduct contains glands that secrete an albumin
(albuminous) coating around the eggs as they pass through. The posterior end of each
oviduct expands to form an ovisac, where the eggs are stored temporarily before being
released. Each oviduct opens separately into the wall of the cloaca through two distinct
openings.
Mating and Fertilization in frog:
Sexually mature frogs gather during the breeding season, which usually occurs in the spring.
They are commonly found in ponds and shallow-water swamps. During mating, the male clasps
the female using his forelimbs. The first finger of the male is swollen, forming what is known as
the nuptial pad, which helps him grip the female securely. The frogs remain in this position for a
period of time, during which the male presses on the female’s body, stimulating her to release
eggs into the water. Simultaneously, the male releases sperm over the eggs, resulting in
fertilization. Although each egg is surrounded by many sperm, only one sperm successfully
fertilizes the egg, forming a fertilized egg (zygote) which represents the beginning of a new
individual. This process of fertilization occurs outside the female’s body and is referred to as
external fertilization.
After external fertilization, the fertilized egg (zygote) undergoes the cleavage stage, leading to
the formation of a tadpole, which has a tail. As the tadpole grows and undergoes morphological
changes (metamorphosis), it gradually loses its tail and gills. The gills are replaced by lungs,
enabling the adult frog to breathe air.
Q: Define: Nuptial pad )‫(وزاري‬
ANS: It is the swollen first finger of the male frog’s forelimb, known as the nuptial pad, which
helps him clasp and grip the female securely during mating. The male presses on the female’s
body, stimulating her to release eggs into the water. At the same time, the male releases
sperm over the eggs, resulting in fertilization.
Q: Compare: The ovary in insects and the ovary in frog. )‫(وزاري‬
ANS:

RamadhanSci 140
Ovary in insect Ovary in frog
A pair of small ovaries, each composed of
several fine tubules called ovarioles. These
ovarioles do not contain lumens (cavities).
Two big ovaries (bigger than the ovaries in
insects). Each ovary in the frog is an irregular,
sac-like structure, appearing as a multi-lobed
(multi-lobed sac) with a gray to blackish color.
The ovaries (or the ovarioles) do not attach
by a mesovarium.
The ovaries are located near the kidney and
are attached to the inner body wall by a
membrane called the mesovarium.
No fat bodies at the anterior end. At the anterior end of each ovary are fat
bodies, similar to those found in the male.
The two lateral oviducts connect to the
posterior part of an ovary (direct connection).
The oviducts do not connect directly to the
ovaries.
Eggs are formed in the ovarioles. Eggs are formed in the ovaries.
Ovarioles in female insects contain oogonia,
oocytes, and nurse cells in addition to other
tissue cells.
Eggs are formed from germinal epithelial cells
lining the ovary.
The oviducts usually do not secrete albumin
(albuminous) coatings, and eggs may be
transported differently.
The oviduct lining contains glands that
secrete albumin (albuminous) layer around
the eggs during their passage.
Often without a specialized storage sac like
the frog’s ovisac.
The posterior end of the oviduct expands into
an ovisac where eggs are temporarily stored
before release. Each oviduct opens separately
into the cloaca.
There are two lateral oviducts, each
connected to the posterior part of an ovary.
These lateral oviducts merge into a single
common oviduct, which then opens into the
vagina, the posterior part of the female
reproductive system.
Insects do not have a similar fimbriae
structure with cilia at the oviduct opening.
The two oviducts in the frog are long, white,
glandular tubes that are coiled. The anterior
end of each oviduct forms a funnel-shaped
structure with a fringed (fimbriae) opening,
whose cilia help move the eggs backward
into the oviduct. Each oviduct opens
separately into the wall of the cloaca through
two distinct openings.
Q: Compare: Testes and ovaries in frog )‫(وزاري‬
ANS:
Testes in frog Ovaries in frog
An elongated, oval (egg-shaped) structure. An irregular, sac-like structure, appearing as a
multi-lobed (multi-lobed sac).
Color: pale yellow. Color: Gray to blackish

RamadhanSci 141
Each testis attached to the kidneys. It is
connected to the inner body wall by a
The ovaries are located near the kidneys and
are attached to the inner body wall by a
membrane called the mesovarium.
Near the anterior end of each testis, there
are several finger-like projections known as
fat bodies.
At the anterior end of each ovary are fat
bodies, similar to those found in the male.
The testes contain seminiferous tubules,
which are responsible for the process of
spermatogenesis (the formation of sperm
cells).
Eggs are formed from germinal epithelial cells
lining the ovary through the process of
oogenesis.
What is the location and function of: Fat bodies. )‫(وزاري‬
ANS:
Location → Near the anterior end of male and female gonads (testes and ovaries) in frog.
Function → Serve as food reserves. The frog uses these fat bodies to support the testis and
the ovary development during the hibernation season (winter).
Q: Justify or Explain: fertilization in frogs is considered external, even though mating occurs
between the male and female. )‫مهم‬ ‫(وزاري‬
ANS: Because fertilization occurs outside the female’s body. The eggs are surrounded by
sperm in the water, and fertilization takes place externally in the aquatic environment.
Q: Justify or Explain: The vas deferens in the male frog transports both sperm and urine.
Or
Q: Justify or Explain: The vas deferens in male frog is also called urogenital duct.
ANS: Because there is no separate, specialized duct for transporting sperm in male frogs.
Instead, there is a single duct (the vas deferens) which carries both urine and sperm at the
same time.
The vas deferens is shared with the kidney ducts, so it is called the urogenital duct. It
transports urine and sperm and opens into the cloaca.
Q: What is the function of each of the following: Vasa efferentia. )‫مهم‬ ‫(وزاري‬
ANS: Sperm pass through the vasa efferentia from the testis to the kidney in the frog.
Q: Functional ducts called the _______ pass through the mesorchium in the frog. )‫مهم‬ ‫(وزاري‬
ANS: Vasa efferentia.

RamadhanSci 142
Q: What is the function of mesorchium in frog? )‫مهم‬ ‫(وزاري‬
ANS: Connects the testes to the inner body wall.
Q: What is the function of mesovarium in frog? )‫(مهم‬
ANS: Connects the ovaries to the inner body wall.
Q: What is the function of each of the following: Swelling of the first finger in frog. )‫(وزاري‬
ANS: The swollen first finger of the male frog’s forelimb, known as the nuptial pad, which
helps him clasp and grip the female securely during mating. The male presses on the female’s
body, stimulating her to release eggs into the water. At the same time, the male releases
sperm over the eggs, resulting in fertilization.
Q: What is the location of each of the following: Glands that secrete albumin coat (layer).
ANS: Linings of oviducts in frog.
Q: Compare: Vas deferens in male insects and vas deferens in male frogs. )‫مهم‬ ‫(وزاري‬
ANS:
Vas deferens in male insects Vas deferens in male frogs
Transports sperm only. Transports both sperm and urine.
Vas deferens is NOT called urogenital duct
and they are specialized in transporting the
sperm.
It is also called urogenital duct because there
is no separate, specialized duct for
transporting sperm in male frogs. The vas
deferens is shared with the kidney ducts.
The two vasa deferentia unite to form the
ejaculatory duct, which extends into the
penis.
The two vasa deferentia do not unite;
instead, each opens separately into the
cloaca.
Q: What is the origin of (or what is responsible for): The albumin coat (layer) in frog. ‫(وزاري‬
)‫مهم‬
ANS: Glands lining the oviducts in frogs.

RamadhanSci 143
Reproduction in Human:
As in all vertebrates, the sexes in humans are separate, but the human reproductive system is
more complex than that of other vertebrates.
Q: Human reproductive system is _________ than that of other vertebrates.
ANS: More complex.
Male reproductive system in Human:
Q/ The male reproductive system in humans consists of __________ and ________.
ANS: Reproductive organs; Accessory glands.
Reproductive Organs, their Number (in parentheses), Structure and Functions:
Testis (2) [Plural: Testes]: Located in the scrotum, which hangs outside the body. This position
helps maintain a lower temperature, suitable for sperm production.
Function → The testes produce sperm and secrete male sex hormones (mainly testosterone).
Epididymis (2) [plural: Epididymides]:
Function → It is the site where sperm mature and where sperm are stored.
Vas deferens (2) [Plural: Vasa deferentia]:
Function → It transports sperm rapidly and also stores them.
Ejaculatory duct (1):
Function → It delivers the sperm to the penis.
Penis (1):
Function → It is the copulatory (or intercourse or mating) organ.
Q: What do the following sentences indicate: Intercourse organ of male human.
ANS: Penis.

RamadhanSci 144
Accessory glands, their Number (in parentheses), Structure and Functions:
Seminal vesicles (2):
Function → It secretes fluid that mixes with the sperm and forms a major part of the semen.
Prostate gland (1):
Function → It secretes part of the seminal fluid.
Bulbourethral glands (2) [also called Cowper’s glands]:
Function → It secretes a mucous fluid that helps sperm movement and also neutralizes the
acidity of the fluid in which sperm swim.
★
‫معظم‬
‫ا‬
‫مهمات‬ ‫وكلهن‬ ،‫سابقة‬ ‫وزارية‬ ‫أسئلة‬ ‫هي‬ ‫لوظائف‬
.
Q1: List the components of the male reproductive system and state the function of each. )‫(وزاري‬
Q2: List the components of the male reproductive organs and mention their functions. )‫(وزاري‬
Q3: List the components of the male accessory glands and describe the function of each. )‫(وزاري‬
Q: What is responsible for (or what is the origin of): Seminal fluid (or semen). )‫(وزاري‬
ANS:
1. Prostate gland
2. Seminal vesicles
3. Cowper’s glands (bulbourethral glands)
Q: Justify or Explain: The testes are not located inside the abdominal cavity in human males.
)‫(وزاري‬
Or
Q: Justify or Explain: The testes located outside the body in human males. )‫(وزاري‬
ANS: To maintain a suitable temperature for sperm production, because the testes need a
temperature lower than the body temperature in order to produce sperm.
Q: The seminal fluid (semen) is produced and secreted by the prostate gland, ________, and
__________. )‫(وزاري‬
ANS: Seminal vesicles; Cowper’s glands (bulbourethral glands).

RamadhanSci 145
Q: What is the location of prostate gland? )‫مهم‬ ‫(وزاري‬
ANS: In the male reproductive system (this alone is enough).
[optional: it is located just below the urinary bladder, in front of the rectum, and surrounds the
upper part of the urethra].
Sperm formation:
The testis in humans is oval-shaped and contains seminiferous tubules. The combined length of
these tubules is approximately 250 meters.
Within the seminiferous tubules, spermatogonia originate. These cells enlarge and undergo
mitotic division to produce two primary spermatocytes, both of which are diploid (2n).
The primary spermatocytes undergo the first meiotic division to produce secondary
spermatocytes, which are haploid (n). These then undergo the second meiotic division, forming
early spermatids, which are also haploid (n).
The early spermatids then differentiate and mature into sperm cells (sperms), which remain
haploid (n).
Q: What are the chromosome sets for each: Early spermatid.
ANS: Haploid (n).
The mature sperm is differentiated into three parts:
- the head,
- the middle piece,
- and the tail.
The head consists of the nucleus and a head cover which contains the acrosome in the front
part (That sentence is nonsense. It should say: “a cap-like structure called the acrosome at the
front of the head.” But sure, let’s not question the holy textbook.)
It is believed that the acrosome’s function is to produce enzyme-like substances that help break
down the egg's membranes at the point of contact between the sperm and the egg, thereby
facilitating the sperm's entry into the egg.
The middle piece contains a core of longitudinal tubules, which are believed to control the
movement of the tail.
Q: What is the location and function of acrosome? )‫مهم‬ ‫(وزاري‬
ANS:
Location → At the front part of the sperm head. Or At the anterior (front) edge of the cap-like
structure covering the nucleus of the human sperm.

RamadhanSci 146
Function → produces enzyme-like substances that help break down the egg's membranes at the
point of contact between the sperm and the egg, thereby facilitating the sperm's entry into the
egg.
Q: Justify or Explain: The acrosome in human sperm is essential for fertilization. )‫مهم‬ ‫(وزاري‬
Or
Q: Justify or Explain: The presence of the acrosome at the front end of the sperm head. ‫(وزاري‬
)‫مهم‬
ANS: The acrosome contains enzymes that digest the membranes of the egg at the site where
the sperm meets the egg, thereby facilitating the sperm’s penetration of the egg’s surface.
Q: What is the location of: Acrosome )‫مهم‬ ‫(وزاري‬
ANS: At the anterior (front) edge of the cap-like structure covering the nucleus of the human
sperm.
Q: Draw with labelling: Mature sperm in human
ANS:

RamadhanSci 147
Q: Draw with labelling: Male reproductive system in human
ANS:
Cowper’s glands

RamadhanSci 148
Female reproductive system in Human:
The female reproductive system in humans consists of two ovaries, two oviducts (also called
fallopian tubes), a uterus, and a vagina. The ovaries are typically smaller than the testes and
contain thousands of eggs (ova). Each egg develops within a Graafian follicle, which increases in
size as it matures. When the follicle reaches full development, it ruptures to release a mature
egg, a process known as ovulation.
During a woman’s reproductive (fertile) years, which typically span about 30 years,
approximately 13 eggs mature each year, meaning only around 300–400 eggs will ever reach
maturity in her lifetime. The remaining eggs degenerate and are reabsorbed by the body.
The oviducts (also called Fallopian tubes) are two slender tubes responsible for transporting
the eggs. The anterior ends of the oviducts have funnel-shaped openings equipped with
fimbriae (finger-like projections) that help capture the egg released from the ovary during
ovulation. The inner lining of the oviducts is ciliated, which helps move the egg toward the
uterus.
Each oviduct opens into the upper lateral sides of the uterus, which is a thick-walled muscular
organ rich in blood vessels and lined with a specialized endometrium. The uterus is designed to
nurture and protect the developing embryo throughout the nine months of pregnancy.
The vagina is a muscular tube adapted to receive the male reproductive organ during
intercourse and also to allow the passage of the baby during childbirth, after it exits the uterus.
The external genitalia of the female are referred to as the vulva, which includes the labia
majora (outer lips) and labia minora (inner lips).
Reproductive Organs, their Number (in parentheses), and Functions:
Ovaries (2):
Function → It produces eggs and is the site where they mature; it also produces the female sex
hormones.
Oviducts (2) [also called fallopian tubes]:
Function → They transport the eggs from the ovary to the uterus, and fertilization usually takes
place within them.
Uterus (1):
Function → It is the chamber where the new individual (embryo) develops.
Cervix (1):
Function → It secretes mucus that facilitates the movement of sperm within the uterus, and
after fertilization, it helps protect the embryo from bacterial infections.

RamadhanSci 149
Vagina (1):
Function → Intercourse (or copulatory or mating) organ of females.
Q: Define: Fallopian tube )‫(وزاري‬
ANS: Fallopian tubes (oviducts) are two slender tubes responsible for transporting the eggs.
The anterior ends of the oviducts have funnel-shaped openings equipped with fimbriae
(finger-like projections) that help capture the egg released from the ovary during ovulation.
The inner lining of the oviducts is ciliated, which helps move the egg toward the uterus.
Each oviduct opens into the upper lateral sides of the uterus. They transport the eggs from
the ovary to the uterus, and fertilization usually takes place within them.
Q: What is the location of fallopian tubes? )‫(مهم‬
ANS: The upper sides of the uterus in the female reproductive system in humans. These tubes
extend from the uterus toward the ovaries. The fallopian tubes transport the egg from the
ovary to the uterus and are the primary site where fertilization occurs.
Fertilization and pregnancy:
Fertilization occurs when sperm enter the vagina during intercourse between the male and
female, usually at or near the time of ovulation. The sperm swim from the vagina through the
cervix into the uterus and then ascend into the fallopian tube (oviduct). Fertilization happens in
the upper third of the fallopian tube if a live, mature egg is present.
If the mature egg descends to the lower part of the fallopian tube before fertilization, it loses its
ability to be fertilized. Typically, only one sperm fertilizes the mature egg. After fertilization, the
resulting zygote forms in the fallopian tube and begins its journey down to the uterus. Upon
reaching the uterus, the embryo implants itself into the thick, vascular lining of the uterine wall.
The embryonic membranes then develop to form a sac surrounding the embryo, which contains
the amniotic fluid to protect and cushion it during development.
At the end of the embryo’s implantation into the uterine wall, the pregnancy stage begins. The
corpus luteum continues to secrete progesterone after day 26 of the menstrual cycle until the
fifth month of pregnancy. After that, it can no longer produce enough progesterone to maintain
the pregnancy. The placenta then takes over this function, acting as an endocrine gland to
supply the necessary amount of progesterone directly to the uterine lining, rather than
releasing it into the bloodstream.
The fetus is ready for birth after approximately nine months of development. Just before labor,
the placenta stops producing progesterone, causing the uterus to begin contracting, this is the
first sign of labor. The cervix then dilates, and the amniotic sac ruptures, releasing the amniotic

RamadhanSci 150
fluid. Following this, the uterus undergoes strong, rhythmic contractions that push the baby out
through the cervix, then the vagina, and finally out of the body.
During pregnancy, the breasts enlarge, and the mammary glands produce milk in response to
hormonal signals. The continuation of milk secretion depends on the baby’s ongoing
breastfeeding.
Q: What is the location of progesterone hormone? )‫مهم‬ ‫(وزاري‬
ANS: In the corpus luteum (after day 26 of the menstrual cycle until the fifth month of
pregnancy) located in the ovaries of a mature female. Progesterone is also secreted by the
placenta (which is located in the uterus) to directly supply the uterine lining, rather than
releasing it into the bloodstream, starting from after the 5th month of pregnancy.
Q: What is the origin of (or what is responsible for) progesterone hormone? )‫مهم‬ ‫(وزاري‬
ANS: Corpus luteum in the ovary (after day 26 of the menstrual cycle until the fifth month of
pregnancy) and placenta in the uterus (starting from after the 5th month of pregnancy).
Q: what is the function of corpus luteum? )‫مهم‬ ‫(وزاري‬
ANS: secretes progesterone hormone (after day 26 of the menstrual cycle until the fifth month
of pregnancy).
Q: What is responsible for each of the following: Breast enlargement in females.
ANS:
Pregnancy, puberty, and the menstrual cycle due to hormones like progesterone, estrogen,
prolactin, and other hormones.
Q: During pregnancy, the mammary glands produce milk in response to hormonal signals. The
continuation of milk secretion depends on ____________.
ANS: The baby’s ongoing breastfeeding.
Menstrual cycle:
In the reproductive system of a sexually mature human female, periodic changes occur.
These changes usually begin when the female reaches puberty (around 12–14 years old) and
take place within what is called the menstrual cycle.
The menstrual cycle includes changes in the ovary that lead to ovulation, as well as changes in
the lining of the uterus.
The menstrual cycle consists of two main parts: the ovarian cycle and the uterine cycle.
1- Ovarian cycle:
The ovarian cycle is controlled by the following hormones:
- Gonadotropic Hormones – hormones that stimulate the gonads (ovaries).

RamadhanSci 151
- Follicle-Stimulating Hormone (FSH) – stimulates the growth of ovarian follicles.
- Luteinizing Hormone (LH) – triggers ovulation and supports corpus luteum function.
The main events of the ovarian cycle can be summarized as follows:
a- Primordial Follicle Stage: The follicle contains an oogonium (a diploid cell, 2n), and the
first meiotic division begins.
b- Primary Follicle Stage: A non-cellular layer called the zona pellucida starts forming
around the developing oocyte.
c- Secondary Follicle Stage: A fluid-filled cavity called the antrum appears, filled with
secretions from granulosa (follicle) cells, blood plasma components, proteins, and other
substances.
d- Mature (Graafian) Follicle Stage: The follicle becomes fully mature. Meiosis I completes,
producing a secondary oocyte and the first polar body.
e- Ovulation Stage: The mature follicle ruptures, releasing the secondary oocyte and first
polar body into the fallopian tube.
f- Corpus Luteum Formation: The ruptured follicle transforms into the corpus luteum,
which secretes hormones like progesterone. If fertilization does not occur, the corpus
luteum degenerates into the corpus albicans.
Q: Draw with labelling: Ovarian cycle stages in sexually mature human female.
ANS:

RamadhanSci 152
Q: What is the origin of (or what is responsible for) corpus luteum? )‫مهم‬ ‫(وزاري‬
ANS: Remains of the ruptured (mature) follicle in the ovary after ovulation.
2- Uterine cycle:
During the ovarian cycle, the female sex hormones estrogen and progesterone are produced.
These hormones affect the inner lining of the uterus (endometrium), causing a series of periodic
changes known as the uterine cycle. This cycle lasts about 28 days and is divided into distinct
phases as follows:
- Days 1–5: The levels of female sex hormones are low, which leads to the shedding of the
uterine lining and its blood vessels. As a result, blood flows out through the vagina, this
is the menstrual period.
- Days 6–13: The ovarian follicle increases its production of estrogen. This causes the
inner lining of the uterus (endometrium) to thicken and become rich in blood vessels
and glands. This phase is called the proliferative phase (or reproduction stage according
to the bible) of the uterine cycle. Ovulation typically occurs on day 14 of a 28-day cycle.
- Days 15–28: The corpus luteum increases its production of progesterone, leading to a
further thickening of the uterine lining and an increase in the activity of uterine glands,
which begin secreting mucus. This phase is called the secretory phase of the uterine
cycle.
During this time, the endometrium is fully prepared to receive a fertilized egg. If pregnancy does
not occur, the corpus luteum degenerates, the levels of sex hormones drop, and the uterine
lining breaks down, starting a new menstrual period.
Ovarian cycle table:
Stage Events
Follicular Stage (Days 1–13) - FSH (Follicle Stimulating Hormone) is
secreted to stimulate the growth and
maturation of ovarian follicles.

RamadhanSci 153
- The maturing follicles produce estrogen,
which helps in the development of the
uterine lining.
Ovulation Stage (Day 14) There is a decrease in the production of
luteinizing hormone (LH) after its peak.
Corpus Luteum Stage (Days 14–28) - The luteinizing hormone (LH) stimulates the
formation of the corpus luteum from the
ruptured follicle.
- The corpus luteum secretes progesterone.
Uterine cycle table:
Stage Events
Menstrual Phase (Days 1–5) The internal lining of the uterus breaks down
and is shed through the vagina.
Proliferative Phase (or ‘forming stage’
according to the bible), Days 6–13
The internal lining of the uterus repairs and
thickens.
Secretory Phase (Days 15–28) The uterine lining becomes highly thickened,
and the glands mature to secrete their fluids.
Q: What is the origin of (or what is responsible for) the estrogen? )‫جدا‬ ‫مهم‬ ‫(وزاري‬
ANS: Ovarian follicles, especially the developing (maturing) follicles which are located in the
ovary, during the follicular phase of the ovarian cycle.
Q: What is the location of:
1. Ovarian follicles
2. Graafian follicles
3. Developing (maturing) follicles
4. Corpus luteum
5. Corpus albicans
ANS: The ovary ☺
Q: During the ovarian cycle, the female sex hormones ______ and ______ are produced.
)‫جدا‬ ‫مهم‬ ‫(وزاري‬
ANS: Estrogen; Progesterone.

RamadhanSci 154
Q: Define: Estrogen )‫(وزاري‬
ANS: Estrogen is a hormone secreted by the ovarian follicles in the human female
reproductive system, especially by the developing (maturing) follicles which are located in the
ovary, during the follicular phase of the ovarian cycle. It helps thicken and repair the internal
lining of the uterus (endometrium), making it vascular and glandular.
Q: What are the hormones secreted by the ovary? What is their importance? Mention the origin
(source) of each one. )‫(وزاري‬
ANS:
1. Estrogen:
Importance (function) → It helps thicken and repair the internal lining of the uterus
(endometrium), making it vascular and glandular.
Origin → Ovarian follicles, especially the developing (maturing) follicles which are
located in the ovary, during the follicular phase of the ovarian cycle.
2. Progesterone:
Importance (function) → It prepares the inner lining of the uterus (endometrium) to
receive and support the developing embryo. It also prevents ovulation and menstruation
during pregnancy by maintaining hormonal balance and supporting early stages of
gestation.
Origin → Corpus luteum in the ovary (after day 26 of the menstrual cycle until the fifth
month of pregnancy) and placenta in the uterus (starting from after the 5th month of
pregnancy).
Q: What is the origin (or what is responsible for): Production of female sex hormones. )‫(وزاري‬
ANS: The ovary, specifically:
Estrogen origin → Ovarian follicles, especially the developing (maturing) follicles which are
located in the ovary, during the follicular phase of the ovarian cycle.
Progesterone origin → Corpus luteum in the ovary (after day 26 of the menstrual cycle until
the fifth month of pregnancy) and the placenta in the uterus (starting from after the 5th
month of pregnancy).
Q: What is the location and function of placenta? )‫(مهم‬
ANS:
Location → Inside the uterus, where it attaches to the wall of the uterus and connects to the
developing fetus through the umbilical cord.
Function → 1. Acts as an endocrine gland to supply the necessary amount of progesterone
directly to the uterine lining, rather than releasing it into the bloodstream, starting from after
the 5th month of pregnancy.
2. Supplies oxygen and nutrients from the mother’s blood to the fetus.

RamadhanSci 155
3. Removes waste products (like carbon dioxide) from the fetus’s blood.
4. Acts as a barrier to some harmful substances (but not all).
★ 2, 3, and 4 are not really mentioned like this in the book but I want you to write it down as
a side note, the main answer is no.1.
Parthenogenesis:
Parthenogenesis is a type of reproduction in which the embryo develops from a non-fertilized
egg. This type of reproduction occurs in some nematodes, crustaceans, and insects (like aphids),
as well as in many species of fish, amphibians, and desert lizards.
Parthenogenesis is common in honeybees. The female bee, or queen, is fertilized by the male
only once in her lifetime. She stores the sperm in a special sac connected to the reproductive
tract, sealed by a muscular valve. When the queen lays eggs, she can either open the valve to
release sperm and fertilize the eggs, or keep it closed, allowing the eggs to develop without
fertilization. Notably, unfertilized eggs give rise to males.
In honeybees, fertilization determines sex:
- Fertilized eggs (diploid, 2n) → develop into females (workers or future queens).
- Unfertilized eggs (haploid, 1n) → develop into males (drones).
In some species, parthenogenesis is the only form of reproduction. For example, certain
populations of whiptail lizards living in the southwestern United States consist entirely of
females. These females are diploid (2n), and before meiosis, their chromosomes duplicate to
become tetraploid (4n). After meiosis, the resulting eggs return to being diploid (2n), and these
diploid eggs develop without fertilization.
Q: Define: Parthenogenesis )‫جدا‬ ‫مهم‬ ‫(وزاري‬
ANS: Parthenogenesis is a type of reproduction in which the embryo develops from a non-
fertilized egg. This type of reproduction occurs in some nematodes, crustaceans, and insects
(like aphids), as well as in many species of fish, amphibians, and desert lizards.
Q: Give an example for each of the following: An animal in which parthenogenesis is common.
)‫جدا‬ ‫مهم‬ ‫(وزاري‬
ANS: Honeybees.
1. Whiptail lizard eggs after meiosis )‫جدا‬ ‫مهم‬ ‫(وزاري‬
2. Whiptail lizard eggs before meiosis
3. Whiptail lizard (the individual itself)
4. Spermatogonia in bees )‫جدا‬ ‫مهم‬ ‫(وزاري‬

RamadhanSci 156
5. Male bees (drones)
6. Female bees
7. Worker bees
8. Queen bee.
ANS:
1. Diploid (2n)
2. Tetraploid (4n)
3. Diploid (2n)
4. Haploid (n)
(Because they’re in males, and male bees are haploid from unfertilized eggs)
5. Haploid (n)
6. Diploid (2n)
7. Diploid (2n)
8. Diploid (2n)
Q: Justify or Explain: Female whiptail lizards are diploid even though they reproduce without
fertilization. )‫جدا‬ ‫مهم‬ ‫(وزاري‬
ANS: Because their chromosomes duplicate before meiosis to become tetraploid (4n), and
after meiosis, the resulting eggs return to diploid (2n), and these diploid eggs develop without
fertilization.
Hermaphroditism (Q/ Define: Hermaphroditism [or a hermaphrodite] ‫جدا‬ ‫مهم‬ ‫)وزاري‬:
Hermaphroditism is a condition where many types of animals possess both male and female
reproductive organs in the same individual. These animals are called hermaphrodites, and a
single individual is capable of producing both eggs and sperm. Most hermaphroditic animals
avoid self-fertilization by exchanging their reproductive cells with another individual. For
example, the earthworm has both male and female organs, but its eggs are fertilized by the
sperm of a mating partner, and vice versa.
Some hermaphroditic animals prevent self-fertilization by having their eggs and sperm mature
at different times (a process called temporal separation).
In contrast, the tapeworm is capable of self-fertilization, meaning its own sperm can fertilize its
own eggs.
Hermaphroditism appears in many invertebrates, such as Hydra, flatworms, annelids, and
certain crustaceans. In vertebrates, hermaphroditism is rare, except in a few species of fish.

RamadhanSci 157
Chapter Qs:
Q1: Write the suitable scientific term for each of the following:
1. ___________: Cells produced by mitosis from primary germ cells that line the
seminiferous tubules.
2. _________: A unicellular organism from green algae, with a green cell and two flagella.
3. __________: An egg-shaped or cylindrical sac structure containing pollen inside.
4. _______: A green, heart-shaped structure that carries both archegonium and
antheridium.
5. _________: Expanded underground stems that store food and grow beneath the soil.
6. _________: A method of vegetative propagation where a branch remains connected to
the parent plant and grows underground.
ANS:
1. Spermatogonia
2. Chlamydomonas
3. Anther.
4. Prothallus
5. Tubers
6. Propagation by layering
Q2: What is the location and function of each of the following:
Acrosome → Location: At the front part of the sperm head. Or At the anterior (front) edge of
the cap-like structure covering the nucleus of the human sperm.
Function: produces enzyme-like substances that help break down the egg's membranes at the
point of contact between the sperm and the egg, thereby facilitating the sperm's entry into the
egg.

RamadhanSci 158
Interstitial cells → Location: In body wall of hydra.
Function: Undifferentiated cells capable of transforming into any cell type when needed.
Corpus luteum → Location: The ovary (remains of the ruptured [mature] follicle in the ovary
after ovulation).
Function: secretes progesterone hormone (after day 26 of the menstrual cycle until the fifth
month of pregnancy).
Accessory glands → Location: Near the beginning of the ejaculatory duct (male insects).
Function: Secrete a mucous fluid that surrounds the sperm and forms a sac-like structure known
as the sperm sac or spermatophore (male insects).
In cockroach (female) ➔ form the egg case (ootheca, or ovisac).
In bees (female) ➔ involved in defense.
In ants (female) ➔ used for trail marking.
Prostate gland → Location: In the male reproductive system (this alone is enough).
[optional: it is located just below the urinary bladder, in front of the rectum, and surrounds the
upper part of the urethra].
Function: It secretes part of the seminal fluid.
Fallopian tubes → Location: The upper sides of the uterus in the female reproductive system in
humans. These tubes extend from the uterus toward the ovaries. The fallopian tubes transport
the egg from the ovary to the uterus and are the primary site where fertilization occurs.
Function: They transport the eggs from the ovary to the uterus, and fertilization usually takes
place within them.
Sporophyte → Location: The sporophyte is the diploid multicellular stage in the life cycle of
plants and some algae. It develops from the fertilized egg (zygote) and is usually found attached
to or growing from the gametophyte. In land plants like mosses, ferns, and flowering plants, the
sporophyte is often the dominant, visible stage (especially in ferns and flowering plants).
Function: Produce spores through meiosis. These spores grow into the haploid gametophyte
generation, continuing the life cycle. Essentially, the sporophyte generates and disperses spores
to enable reproduction and genetic diversity.
Stigma → Location: The topmost part of the pistil.
Function: Receives and traps pollen grains; sticky surface helps retain pollen, which then passes
through it to the style and eventually reaches the ovary for fertilization.
Micropyle → Location: At the top of the nucellus.
Function: It allows the pollen tube to enter the embryo sac in order to perform double
fertilization.

RamadhanSci 159
Torpedo stage → Location: Occurs within the embryo of a developing seed, inside the ovule,
which is found in the ovary of the female reproductive organ in flowering plants.
Function: The torpedo stage is a key stage in embryonic development of flowering plants.
During this stage:
- the embryo takes on a torpedo-like shape (closely resembling a cylindrical form).
- the cotyledons are clearly formed (one in monocotyledon and two in dicotyledon).
Q3: Compare between the following:
Donor cell vs. Recipient cell in the sexual reproduction of bacteria:
Donor cell Recipient cell
Contains fertility factor (F factor). Does not contain fertility factor (F factor).
Contains sex pili (sex pilus then transforms
into conjugation bridge).
Does not contain sex pili.
It qualifies as a male cell. It qualifies as a female cell
Haploid (n) Haploid (n)
Part of its chromosome is transferred to the
recipient cell during conjugation.
It receives part of the donor cell's
chromosome during conjugation.
Archegonium vs. Antheridium:
Archegonium Antheridium
Female gametangium Male gametangium
Haploid (n) Haploid (n)
Inside it, the female gametes (egg cell) are
formed.
Inside it, the male gametes (a number of
sperms) are formed.
Fertilization takes place inside the
archegonium.
The sperms swim out to meet the egg.
Located at the broad end of the prothallus. Located at the pointed end of the prothallus.
Sepals vs. Petals:
Sepals Petals
Sepals are collectively known as the calyx. Petals are collectively known as the corolla.
Sepals are non-essential part of the flower
(sepals do not directly participate in sexual
reproduction or seed formation).
Petals are non-essential part of the flower
(petals do not directly participate in sexual
reproduction or seed formation).
Function: Protects the flower bud before it
opens.
Function: Attract insects that aid in
pollination.

RamadhanSci 160
They are usually green, though sometimes
colorful.
They vary in shape, size, and color among
different plants.
Sepals remain attached to the lower part of
the flower (the receptacle), and their number
differs among plants.
Typically, the number of petals equals the
number of sepals or is double that. For
example, the iris has three sepals and three
petals, while the rose has many more petals
than sepals.
Cross-pollination vs. Self-pollination:
Self-pollination Cross-pollination
the anther of a flower to the stigma of the
same flower, or to the stigma of a different
flower on the same plant.
the anther of one flower to the stigma of a
flower on another plant of the same kind,
and sometimes even to other varieties within
the same species.
Occurs in many kinds of plants, such as
wheat, barley, rice, cotton, beans, peas, and
Occurs in many plants.
Fruits and seeds formed are smaller in size Fruits and seeds formed are larger in size.
The fruits and seeds formed are fewer in
quantity and grow more slowly.
The fruits and seeds formed are greater in
quantity and grow more quickly.
Artificial fruits vs. Natural fruits:
★ In the Arabic book the Q says ‫ا‬
‫واالثمار‬ ‫الطبيعي‬ ‫العذري‬ ‫الثمار‬
‫االصطناعي‬ ‫العذري‬ so the Q might
present like “compare natural parthenocarpic fruits and artificial parthenocarpic fruits.”
However, I will answer both Qs below:
Natural fruits (in general) Artificial fruits
Develop naturally with or without fertilization
of the ovule in the ovary.
Develop without fertilization.
Seeded or seedless fruits Seedless fruits
The fruits are formed naturally without
human intervention.
Fruits are produced by spraying or injecting
the ovaries of some flowers with specific
plant hormones.
The ovaries of these plants' flowers
(especially the natural parthenocarpic fruits)
are believed to have a high hormonal content
that stimulates them to form fruits.
They do not have a high hormonal content in
their ovaries.

RamadhanSci 161
Examples: apples, and mango.
Examples of seedless fruits: pineapples, navel
oranges, and some types of grapes.
Examples include some fruits produced by
ovary spraying like seedless watermelon and
seedless cucumbers.
Natural parthenocarpic fruit Artifical parthenocarpic fruit
It is the growth and ripening of the ovary and
its transformation into a fruit without the
process of fertilization.
Ditto.
Seedless fruits Seedless fruits
The fruits are formed naturally without
human intervention.
Fruits are produced by spraying or injecting
the ovaries of some flowers with specific
plant hormones.
The ovaries of these plants' flowers are
believed to have a high hormonal content
that stimulates them to form fruits.
They do not have a high hormonal content in
their ovaries.
Examples include pineapples, navel oranges,
and some types of grapes.
Examples include some fruits produced by
ovary spraying like seedless watermelon and
seedless cucumbers.
Compound fruits vs. Aggregate fruits:
Compound fruits (multiple fruits) Aggregate fruits
Formed from a group of flowers. Formed from many separate carpels of a
single flower.
Each flower forms a fruit, and they remain
connected to each other at maturity.
The individual fruitlets are connected to a
single receptacle.
Example: Pineapple Example: Blackberries
Reproduction by stolons vs. Reproduction by rhizomes:
Reproduction by stolons Reproduction by rhizomes
One of the types of natural vegetative
propagation.
A natural vegetative propagation way which
most of the weeds (perennial weeds) and
ferns reproduce by.
Example: Strawberries Example: Garden grass and iris
A horizontal stem, known as a stolon, can
extend up to a meter along the surface of the
ground.
It happens through the formation of
terrestrial stems that extend beneath the soil
surface, called rhizomes.

RamadhanSci 162
At specific points called nodes (or knots) on
the stolon, new vertical shoots (young plants)
begin to grow. From each node, new roots
grow downward into the soil, while new
stems and leaves grow upward.
Adventitious roots grow from these stems
into the soil, while green parts (stems and
leaves) emerge from buds above the ground.
Terrestrial stems (which are perennial stems)
extend rapidly through the growth of their
apical buds (also called terminal buds),
covering new ground quickly.
This new plant can naturally separate from
the mother plant when the stolon connecting
them dies, or it can be manually detached
and replanted elsewhere.
If these rhizomes happen to break into pieces
during soil tilling (e.g. plowing), each piece
can grow into a new plant.
Oviparous insects vs. Ovoviviparous insects:
Oviparous insects Ovoviviparous insects
Insects that reproduce by laying eggs are
called oviparous, and the process is known as
ovipary.
Insects retain the fertilized eggs inside their
bodies, and the process is known as
ovovivipary, and such insects are referred to
as ovoviviparous.
Female insects typically lay their fertilized
eggs in environments suitable for the growth
of the offspring. They may deposit eggs in
holes dug using the ovipositor, attach them to
plant leaves, or insert them into plant stems.
The embryo is retained in the common
oviduct.
The embryo develops and the eggs hatch
away from the mother’s body, after which the
young are released outside.
The embryos develop and the eggs hatch
internally (inside the mother’s body), after
which the young are released.
Conjugation vs. Self-fertilization in Paramecium:
Conjugation Autogamy (self-fertilization)
The male nucleus in each of the two
conjugated organisms is exchanged and
unites with the female nucleus to form a
compact nucleus containing the complete
number of chromosomes (2n).
There is no exchange of nuclei. Instead, the
two primary micronuclei, each containing
half the number of chromosomes (n), unite
to form a single identical nucleus (synkaryon).
The compact nucleus (or united nuclei) is
heterozygous.
The compact nucleus (or united nuclei or
synkaryon or identical nucleus) is
homozygous.

RamadhanSci 163
Q4: Complete the following statements:
1. Sperm cells are formed in __________, which consist of a large number of __________.
2. Reproduction in viruses occurs through two integrated cycles: the __________ cycle and
the __________ cycle.
3. Paramecium reproduces sexually by __________ and __________.
4. The anthocyanin pigment accumulates in mature fruits such as __________ and
__________.
5. The ideal life cycle of Hydrozoa consists of two stages: __________ and __________.
6. Planaria reproduces sexually by __________.
7. The reproductive organs of insects consist of two main parts: __________ and
__________.
8. The total length of seminiferous tubules in the human testes is __________.
9. A mature human sperm is divided into three parts: __________, __________, and
__________.
10. The secretion of milk in the human female depends on __________.
ANS:
1. Testes; Seminiferous tubules.
2. Lytic; Lysogenic.
3. Conjugation and autogamy (self-fertilization).
4. Grapes and pears.
5. Asexual stage (Polyp); Sexual stage (Medusa).
6. Cross-fertilization between hermaphrodites
★ The Arabic edition of the book uses the term “asexually.” In this context, the correct
answer would be: fragmentation and regeneration + binary fission.
7. Internal reproductive insects; External reproductive insects.
8. 250 meters.
9. Head, middle piece, and tail.
10. Hormonal signals. The continuation of milk secretion depends on the baby’s ongoing
breastfeeding.
Q5: Define the following scientific terms:
Double fertilization: One of the sperm cells fuses with the egg cell to form a zygote with a
diploid (2n) number of chromosomes. The second sperm cell fuses with the two polar nuclei to
form the endosperm nucleus, which has a triploid (3n) chromosomal set. The fusion of one
sperm with the egg nucleus and the other with the two polar nuclei is called double fertilization,
a unique feature of flowering plant.

RamadhanSci 164
Testa: Is the covering of the egg that transforms into the seed coat, which is called the testa (pl.:
testae).
False fruits: These are fruits that develop from floral parts other than the ovary, such as the
receptacle (as in apples) or the flower coverings (as in berries).
Multiple fruits: They can also be called compound fruits and are formed from a group of
flowers. Each flower forms a fruit, and they remain connected to each other at maturity, as in
the case of pineapple.
Pollen tube: It is the narrow structure that grows from the pollen grain after landing on the
stigma. Usually, each pollen grain produces one pollen tube. The pollen tube grows and
penetrates the stigma and style until it reaches the ovule, which contains the egg cell. Although
many pollen tubes may form, only one reaches the egg. As the pollen tube grows, the
generative cell undergoes one division (mitosis) to produce two sperm cells. Thus, the pollen
tube contains a tube cell and two sperm cells, and at this stage, it represents the mature male
gametophyte, ready for fertilization.
When the pollen tube reaches the ovule, it penetrates the micropyle, enters the nucellus, and
then moves into the embryo sac, where it releases its contents. One of the sperm cells fuses
with the egg cell to form a zygote with a diploid (2n) number of chromosomes. The second
sperm cell fuses with the two polar nuclei to form the endosperm nucleus, which has a triploid
(3n) chromosomal set. The fusion of one sperm with the egg nucleus and the other with the
two polar nuclei is called double fertilization, a unique feature of flowering plants.
Nuptial pad: It is the swollen first finger of the male frog’s forelimb, known as the nuptial pad,
which helps him clasp and grip the female securely during mating. The male presses on the
female’s body, stimulating her to release eggs into the water. At the same time, the male
releases sperm over the eggs, resulting in fertilization.
Graafian follicle: It is a mature ovarian follicle in a sexually mature human female that contains a
single developing oocyte (egg cell). Inside this follicle, the oocyte undergoes its final stages of
growth and maturation. As the follicle enlarges, it eventually ruptures during ovulation,
releasing the mature egg into the fallopian tube. The remnants of the ruptured follicle then
transform into the corpus luteum within the ovary, which secretes hormones such as
progesterone to support a potential pregnancy.
Parthenogenesis: Is a type of reproduction in which the embryo develops from a non-fertilized
egg. This type of reproduction occurs in some nematodes, crustaceans, and insects (like aphids),
as well as in many species of fish, amphibians, and desert lizards.

RamadhanSci 165
Q6: Choose the correct answer:
1. Hydra reproduces in many ways except:
a) Budding
b) Regeneration
c) Fission
d) Gametes
ANS: c) Fission.
2. Alternation of generations occurs in the life cycle of:
a) Bacteria
b) Plasmodium
c) Amoeba
d) Polytrichum
ANS: d) Polytrichum (or Kingdom Plantae in the Arabic book).
3. The number of spermatids formed at the end of spermatogenesis is:
a) 4
b) 2
c) 6
d) 8
ANS: a) 4.
4. Bacteria reproduce asexually by:
a) Budding
b) Binary fission
c) Regeneration
d) Spore formation
ANS: b) Binary fission.
5. Paramecium reproduces asexually by:
a) Binary fission
b) Regeneration
c) Budding
d) Spore formation

RamadhanSci 166
ANS: a) Binary fission (transverse binary fission to be more specific).
6. Which of the following organisms does not reproduce asexually by binary fission?
a) Paramecium
b) Bacteria
c) Euglena
d) Black bread mold
ANS: d) Black bread mold.
7. Hydra reproduces asexually by:
a) Budding and binary fission
b) Budding, fragmentation, and regeneration
c) Spore formation and binary fission
d) Fragmentation and regeneration
ANS: b) Budding, fragmentation and regeneration.
8. The shape of leaf venation in dicot plants is:
a) Netted
b) Parallel
c) Vertical
d) Crossed
ANS: a) Netted.
9. Which of the following organisms reproduces by fragmentation and regeneration?
a) Planaria
b) Hydra
c) Bacteria
d) None of the above
ANS: There are two correct answers here: Planaria and Hydra.
Q7: Write a short summary about each of the following:
1. The role of bees in plant pollination: Bees play a crucial role in cross‑pollination, which leads
to larger fruits, higher yields, and faster plant growth compared to self‑pollination. Their
contribution to agriculture is of immense economic value, estimated at over 200 billion USD
globally each year. For this reason, farmers are encouraged to keep beehives on or near their
farms to ensure efficient cross‑pollination and to achieve larger quantities of high‑quality
produce.
2. Cleft grafting: Cleft grafting is a method of vegetative propagation where the stem of the
stock plant is cut horizontally near the soil surface. A vertical split (cleft) is then made in the
center of this cut. A scion branch, typically containing two or three buds, is taken and its base is
sharpened or beveled on both sides, similar to the shape of a wedge or pencil. The prepared
scion is carefully inserted into the cleft, ensuring that the cambium tissues of both the scion and

RamadhanSci 167
the stock match up on at least one side to promote proper growth and union. The grafted area
is then tied securely, and in some cases, covered with grafting wax to protect it from drying out
or infection. If the stem of the stock is large, more than one scion may be inserted into different
parts of the split to ensure successful grafting. It is important to note that grafting is generally
only successful when the scion and the stock share similar characteristics, meaning they must
belong to the same botanical family or group. For example, orange cannot be grafted onto
peach, as they are from different families. However, orange can be grafted onto lemon, and
peach can be grafted onto plum, since they are more closely related.
NOTE: In the Arabic version of the book, they mention ‫إجاص‬ ‫مع‬ ‫خوخ‬ — meaning peach with pear,
not plum. But you should be familiar with both, because the exam questions can be annoyingly
inconsistent.
3. Male reproductive system in frog: The male reproductive system in the frog consists of the
following:
- A pair of testes, each attached to the kidneys. Each testis is an elongated, oval (egg-
shaped) structure with a pale yellow color. It is connected to the inner body wall by a
- Near the anterior end of each testis, there are several finger-like projections known as
fat bodies, which serve as food reserves. The frog uses these fat bodies to support testis
development during the hibernation season (winter).
- The testes contain seminiferous tubules, which are responsible for the process of
spermatogenesis (the formation of sperm cells).
- The vasa efferentia are 10–12 small ducts and connect to the seminiferous tubules. The
vasa efferntia also connect to the kidney tubules.
- The vas deferens are two ducts that are shared with the kidney canals; for this reason,
they are called the urogenital ducts. These ducts carry both urine and sperm, and they
open into the cloaca. In some frogs, the posterior part of the vas deferens expands to
form a seminal vesicle, which serves as a storage site for sperm. Frogs do not have
external male copulatory organs.
4. Stages of embryo development in dicotyledonous plants:
We can summarize the growth stages in dicotyledons embryos as follows:
the endosperm.
begin to appear.

RamadhanSci 168
monocotyledons).

RamadhanSci 169
Q8: Write down what you know about:
1. Explain the steps of asexual reproduction in bacteria, using a diagram.
ANS:
Bacteria reproduce asexually by binary fission.
This can be summarized as follows:
- The bacterial chromosome attaches to the plasma membrane at a specific site,
indicating that the cell is ready for division.
- The bacterial cell prepares for binary fission by expanding its cell wall and plasma
membrane, causing the entire cell to enlarge.
- The division of DNA produces two identical chromosomes, and at the same time, the cell
wall and plasma membrane begin to pinch inward.
- As a result of this stretching, the two chromosomes move in opposite directions within
the cell. At the same time, the cytoplasm spreads, and the overall cell elongation
increases.
- The cell divides, producing two identical daughter cells.

RamadhanSci 170
2. Alternation of generations in plant reproduction.
ANS:
In the plant kingdom, alternation of generations is a clear and important feature of plant
reproduction.
It means that the complete life cycle of a plant includes two distinct stages:
- the sporophyte stage, and
- the gametophyte stage, as explained below:
1- Sporophyte:
This is the asexual stage that produces spores. Its cells contain the full set of chromosomes (2n).
When this stage matures, some of its cells, known as mother cells, undergo meiosis to form
spores. As a result of this division, the spores carry half the original number of chromosomes
(n), and these spores mark the beginning of the gametophyte stage.
2- Gametophyte:
This is the sexual stage of the plant life cycle, during which gametes are produced. After the
fertilization of male and female gametes, the sporophyte stage begins, this marks the
alternation of generations.

RamadhanSci 171
As we move up the evolutionary ladder of plants, we observe that the gametophyte becomes
progressively smaller. This reduction reaches its peak in flowering plants, where the
gametophyte is very reduced. In contrast, the sporophyte becomes more dominant, especially
in modern terrestrial plants. This shift is due to plant adaptation to life on land, as adaptations
increased, the sporophyte stage became more prominent, while the gametophyte stage was
gradually reduced.
3. The steps of tissue transplantation for the date palms.
ANS:
The tissue plantation for date trees can be summarized as follows:
1. One of the offsets is separated from the mother date palm plant, preferably an actively
growing offset.
2. The apical growing part is extracted from the offset, and this requires a sterilized
medium to prevent contamination of the extracted tissue.
3. The apical growing part is partitioned (cut) into small pieces, which must contain active
living cells.
4. The living tissues are planted in special culture media that contain suitable nutrients.
The cultivation is carried out under sterile conditions around and within the tissue
cultures, while ensuring that temperature and humidity levels are appropriate.
5. They are transferred to a special glass container and cared for under good sterile
conditions until they reach the stage where they are ready to be planted in the natural
environment.
4. The mating process in earthworms.
ANS:
Copulation in earthworms usually occurs at night, especially during warm and humid weather
in spring and summer. After mating begins, each worm extends the front part of its body out of
the burrow so that the ventral surfaces of both worms are pressed together in opposite
directions. This positioning ensures that the clitellum (saddle) of each worm is aligned with the
openings of the spermathecae of the other worm. The two worms stick together with the help
of mucus secreted by the clitellum. Their bodies are coated in a slimy sheath extending from
segment 8 to just before the clitellum. During mating, both worms exchange sperm. The sperm
is released from the vas deferens openings located on the ventral side of segment 15 and moves
under the mucus sheath toward the clitellum of the other worm, entering its spermathecae.
This is known as cross-fertilization because each worm donates sperm to the other.

RamadhanSci 172
After separating, the clitellum of each worm begins to secrete a mucous ring that forms a tube-
like structure around it, called a cocoon. As the worm moves, the cocoon slides forward along
its body. When it reaches segment 14, where the oviduct openings are located, eggs are
5. The events of the uterine cycle in the human female.
ANS:
Uterine cycle:
During the ovarian cycle, the female sex hormones estrogen and progesterone are produced.
These hormones affect the inner lining of the uterus (endometrium), causing a series of periodic
changes known as the uterine cycle. This cycle lasts about 28 days and is divided into distinct
phases as follows:
- Days 1–5: The levels of female sex hormones are low, which leads to the shedding of the
uterine lining and its blood vessels. As a result, blood flows out through the vagina, this
is the menstrual period.
- Days 6–13: The ovarian follicle increases its production of estrogen. This causes the
inner lining of the uterus (endometrium) to thicken and become rich in blood vessels
and glands. This phase is called the proliferative phase (or reproduction stage according
to the bible) of the uterine cycle. Ovulation typically occurs on day 14 of a 28-day cycle.
- Days 15–28: The corpus luteum increases its production of progesterone, leading to a
further thickening of the uterine lining and an increase in the activity of uterine glands,
which begin secreting mucus. This phase is called the secretory phase of the uterine
cycle.
During this time, the endometrium is fully prepared to receive a fertilized egg. If pregnancy does
not occur, the corpus luteum degenerates, the levels of sex hormones drop, and the uterine
lining breaks down, starting a new menstrual period.
Uterine cycle table:
Stage Events
Menstrual Phase (Days 1–5) The internal lining of the uterus breaks down
and is shed through the vagina.
Proliferative Phase (or ‘forming stage’
according to the bible), Days 6–13
The internal lining of the uterus repairs and
thickens.
Secretory Phase (Days 15–28) The uterine lining becomes highly thickened,
and the glands mature to secrete their fluids.

RamadhanSci 173
Q9: Explain what happens in each of the following cases:
1. Disappearance of the corpus luteum during the fourth month of pregnancy.
ANS:
If the corpus luteum disappears during the fourth month of pregnancy, it usually does not affect
the pregnancy.
By the end of the first trimester (around the 3rd–4th month), the placenta takes over the
production of progesterone and estrogen. These hormones maintain the uterine lining and
support pregnancy.
So, after the fourth month, the corpus luteum is no longer essential, its disappearance has no
harmful effect, because the placenta has already assumed its function.
If it disappeared before the placenta took over (before about 10–12 weeks), it would lead to
miscarriage due to a drop in progesterone.
2. The position of the testes inside the human body.
ANS:
If the testes remain inside the abdominal cavity instead of descending into the scrotum, the
higher abdominal temperature disrupts normal spermatogenesis, resulting in reduced sperm
count or infertility. This condition can also increase the risk of complications such as testicular
cancer and hormonal issues.
3. Absence of cilia in the lining of the fallopian tube.
ANS:
If cilia are absent in the lining of the fallopian tube, the movement of the ovum from the ovary
to the uterus will be impaired because cilia normally help in pushing the egg along the tube.
This can lead to delayed transport or failure of the egg to reach the uterus, increasing the risk of
ectopic pregnancy. Fertility may be reduced or lost as the sperm and egg may fail to meet in the
proper location for fertilization.
4. Injection or spraying of some flower ovaries with specific plant hormones.
ANS: Artificial parthenocarpy i.e., transforming the ovary into a fruit without fertilization,
resulting in a seedless fruit.
Q10: Explain with diagrams:
1. The stages of sperm formation (spermatogenesis).
ANS:

RamadhanSci 174
2. The three layers of a fruit.
ANS:
3. The reproductive system of Planaria.
ANS:
Exocarp

RamadhanSci 175
4. Male and female reproductive system in insects.
ANS:
Male
Female

RamadhanSci 176
Q11: Justify and Explain the following:
1. Reproduction ensures the survival of species.
ANS: Living organisms have persisted on Earth for millions of years and gradually evolved from
simple to more complex forms because of their ability to reproduce. Without reproduction,
species would not be able to continue or survive across generations.
All organisms must produce new individuals similar to itself to preserve the species. Organisms
don’t need reproduction to survive but they need it for continuity of their generations.
Reproduction differs from other life activities like digestion, respiration, circulation, and
2. Alternation of generations is considered the best mode of reproduction in plants.
ANS: Because it combines both sexual and asexual reproduction in one life cycle. The sexual
phase (gametophyte) produces genetic variation through gamete formation and fertilization,
increasing adaptability and evolution. The asexual phase (sporophyte) grows faster and
produces a large number of spores without fertilization, allowing rapid multiplication and
colonization. This combination provides both genetic diversity and high reproductive efficiency,
making it the most advantageous mode of reproduction in plants.
3. In some species, only certain individuals participate in reproduction.
ANS: Because this division of labor increases the efficiency and survival of the colony or group.
For example, in social insects such as bees, ants, and termites, the queen and a few males are
responsible for reproduction, while the rest of the individuals (workers and soldiers) perform
tasks like food collection, defense, and care of the young. This specialization ensures that the
reproductive individuals can focus on producing offspring while the non‑reproductive members
support and protect the colony, leading to better survival and success of the species.
4. In asexual reproduction, some organisms disappear when environmental conditions change.
ANS: Because all the offspring are genetically identical to the parent, resulting in no genetic
variation. Without variation, the population cannot adapt to new or unfavorable conditions
such as changes in temperature, availability of food, or the spread of diseases. As a result, if the
environment becomes unsuitable, the entire population may be unable to survive and can
disappear.
5. Humans often use artificial fertilization.

RamadhanSci 177
ANS: This is to ensure the process of fertilization (cross-pollination) as in palms and to obtain
abundant yield, good quality, and faster growth.
Note: Since the question does not specify whether it refers to plants, the answer can be
extended to include humans and animals. Artificial fertilization in humans and some animals is
used to help couples or breeders who are unable to achieve natural conception due to infertility
problems. In this method, sperm is collected and either artificially introduced into the female
reproductive tract or combined with the egg outside the body using techniques such as in vitro
fertilization (IVF). This process increases the chances of pregnancy in cases of low sperm count,
blocked fallopian tubes, or other reproductive issues, allowing couples to have children when
natural conception is not possible. (This topic will be discussed further in Chapter 4.)
6. A large number of pollen grains are produced.
ANS: To increase the chances of successful fertilization. Since pollen grains are carried by wind,
water, or animals, many can be lost or fail to reach the stigma of a compatible flower. Producing
a large quantity ensures that enough pollen grains will arrive to fertilize the ovules, leading to
successful seed and fruit formation. This strategy improves the likelihood of reproduction,
especially in plants that rely on external agents for pollination.
7. The presence of a micropyle in the ovule and seed.
ANS: The micropyle is a small opening in the ovule and later in the seed that allows the entry of
the pollen tube during fertilization. Its presence is essential because it guides the pollen tube to
reach the egg cell inside the ovule for successful fertilization. After fertilization, the micropyle
also facilitates the entry of water during seed germination, which is crucial for activating the
embryo and starting the growth process.
8. The presence of Cowper’s gland, prostate gland, and seminal vesicle in the male reproductive
system.
ANS: Because these glands produce seminal fluid that nourishes and protects the sperm,
providing an environment that helps them move and survive during their journey to fertilize the
egg.
9. Viruses can grow and reproduce only inside living cells but lose this ability outside.
ANS: Because viruses lack cellular organelles and essential enzyme systems needed for
respiration, protein synthesis, and nucleic acid replication, they cannot live independently and
must rely on a host cell to reproduce and carry out vital functions.
10. The tail of a virus secretes enzymes when it attaches to a bacterial cell.

RamadhanSci 178
ANS: Because this enzyme can weaken the chemical bonds in the bacterial cell wall
(decomposes the cell wall) at the site of attachment. This leads to the formation of a small pore
through which the viral DNA (or nucleic acids) enter the host cell.
11. Farmers are advised to keep beehives on their farms.
ANS: To ensure cross-pollination and, as a result, obtain larger quantities of high-quality
produce.
12. The ripening of fruits and seeds leads to the inhibition of the plant’s vegetative growth.
ANS: Because the plant directs most of its energy and nutrients toward developing and
maturing the fruits and seeds. This shift in resource allocation reduces the energy available for
producing new leaves, stems, and roots, causing a slowdown or temporary halt in vegetative
growth until seed dispersal is complete.
13. Reproduction by spores is one of the most efficient forms of asexual reproduction.
ANS: Because a single organism can produce a very large number of lightweight spores that can
be easily dispersed by wind, water, or animals. This method is fast, as spores can grow directly
into new individuals without fertilization. Moreover, spores have resistant walls that allow them
to survive harsh environmental conditions, ensuring the species can persist until conditions
become favorable for growth.
14. The function of the accessory glands varies in insects.
ANS: Because in some insects, the accessory glands are responsible for forming the egg case
(ootheca, or ovisac), as in female cockroaches. In other cases, they may be used for defense, as
in worker bees, or for marking trails, as in ants. In males, they secrete a mucous fluid that
surrounds the sperm and forms a sac-like structure called sperm sac (or spermatophore).
15. Binary fission in planaria is considered a fast method of reproduction.
ANS: Binary fission is a rapid method of reproduction in planaria and is often observed when
there is a decline in their population, especially under experimental conditions. In this process,
the organism divides into two identical individuals without the need for gametes or fertilization.
Because it requires less time and energy than sexual reproduction, binary fission allows planaria
to quickly increase their population when environmental conditions are favorable.

RamadhanSci 179
2016/3
Q1: A- Define: Cross pollination.
C- Draw with labelling: Sexual reproduction in Chlamydomonas.
Q2: A- Justify or Explain:
1. The virus secretes an enzyme when attached to the bacterial cell.
5. Self-fertilization does not occur in planaria.

RamadhanSci 180
Q3: A- Fill in thee blank:
3. Conjugation in bacteria between two cells: ________ and ________.
4. Paramecium reproduces sexually in two ways: ___________ and ___________.
5. The number of chromosome sets in the endosperm nucleus is ______, while in the
sporophyte it is ______.
Q4: What is the function of each of the following: Prostate gland, fat bodies.
Q5: A- What happen in each of the following cases:
- Injection or spraying of some flower ovaries with specific plant hormones.
- The activity of the accessory glands in insects.
B- Compare: Monocotyledon and dicotyledon plants
Q6: B- What is the type of asexual reproduction for each: Euglena, bougainvillea, potatoes,
turmeric, Hydra.
C- What is the origin of each: Tube cell, cocoon, Spermatogonia of Hydra.
I’ll stop here for now. I’ll be uploading more translated questions with answers on my channel,
so make sure you don’t miss out.

احياء السادس العلمي - الفصل الثالث (التكاثر) منهج متميزين/كلية بغداد/موهوبين

More Related Content

Similar to احياء السادس العلمي - الفصل الثالث (التكاثر) منهج متميزين/كلية بغداد/موهوبين (20)

Recently uploaded (20)

احياء السادس العلمي - الفصل الثالث (التكاثر) منهج متميزين/كلية بغداد/موهوبين