Professional studies slideshare(activity 2)
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This document contains notes from a student named Zanele Patience Ndebele on various biology topics. It includes sections on cell division (mitosis), photosynthesis, human evolution, and references. The sections describe the stages of mitosis and cell cycle, the process of photosynthesis and its importance, key figures in the theory of evolution like Darwin and Lamarck, and evidence that supports the theory of evolution such as fossils and DNA similarities. The notes provide information on chromosomes, cell structure, and the role of plants in producing oxygen.
![THE PHASES OF THE CELL CYCLE
The cell cycle includes the following phases:
Interphase (include G1- , S- [DNA synthesis] and G2
phase)
Prophase
Metaphase
Anaphase
Telophase
The result is 2 identical cells.](https://image.slidesharecdn.com/professionalstudiesslideshareactivity2-140307055725-phpapp01/85/Professional-studies-slideshare-activity-2-4-320.jpg)
Professional studies slideshare(activity 2)
- 1. UNIT ONE CELL DIVISION (MITOSIS) ZANELE PATIENCE NDEBELE 201243373 201243373@STUDENT.UJ.AC.ZA
- 2. CHROMOSOMES Chromosomes form when the chromatin network in the nucleus of the cell, coil up, shortens and thickens. Each organism has a specific amount of chromosomes. All humans have 46 chromosomes. These chromosomes are arranged in identical pairs called homologous chromosome pairs – Therefore humans have 23 homologous pairs of chromosomes. These chromosomes is only visible during cell division processes. One chromosome consist of 2 chromatids and one centromere that attach the chromatids together. Each chromatid consist of genes which in turn consist of DNA.
- 3. CHROMOSOME STRUCTURE X and Y chromosomes: gonosomes/sexchromosomes Colored bands represents different genes
- 4. THE PHASES OF THE CELL CYCLE The cell cycle includes the following phases: Interphase (include G1- , S- [DNA synthesis] and G2 phase) Prophase Metaphase Anaphase Telophase The result is 2 identical cells.
- 5. Why is Mitosis important? Allow an organism to grow. Repairs damaged cells/tissue. Replace dead cells/tissue. Reproduction in some simple organisms.
- 6. Where does Mitosis take place? In all somatic cells (include all body cells and excludes the sex cells – sperm/egg cells)
- 7. The process of Mitosis. CONSIST OF A FEW PHASES: INTERPHASE PROPHASE METAPHASE ANAPHASE TELOPHASE
- 8. INTERPHASE Cell builds up enough energy for division process. DNA replication occurs Cell look normal, like before division
- 9. PROPHASE Nuclear envelope and nucleolus disappear. Chromatin become more tightly coiled, and condenses into individual chromosomes. Chromosomes arrange randomly in the cell. Centrioli move to opposite poles, with spindle fibers stretching between them.
- 10. METAPHASE The centrioli reached the opposite poles with the spindle fibers in between. The chromosomes arrange randomly on the equator, each single chromosome attaching to a separate spindle fiber by means of the centromere.
- 11. ANAPHASE The spindle fibers pull tight. The centromers attaching the chromatids of the chromosomes split in half. Daughter chromosomes move to opposite poles.
- 12. EARLY TELOPHASE – KARYOKINESIS (DIVISION OF NUCLEUS Daughter chromosomes reach poles. Nuclear envelope surrounds chromosomes. Nucleolus reappear at each pole. Chromosomes become less condense forming chromatin. Two identical nuclei has been formed
- 13. LATE TELOPHASE – CYTOKINESIS (DIVISION OF THE CYTOPLASM) Invagination of the cytoplasm and plasma membrane occurs. (Cleavage furrow forms in animal cells and a cytoplasmic plate forms in plant cells) Continues until the cell in divided into 2 separate cells. (Identical to one another and to the original cell)
- 14. MITOSIS PROCESS
- 16. Photosynthesis A process that converts carbon dioxide into organic compounds
- 17. In other words: The chemical process by which plants capture sunlight and use it to convert carbon dioxide and water into food.
- 18. Green plants Flowers Trees Some algea A few various forms of bacteria **Mostly flowers and trees**
- 19. These include:
- 20. The plants/algea/bacteria Other living beings such as animals Even humans!!
- 22. Stomates Microscopic hole in the stem and leaves of plants This is where carbon dioxide enters the plant
- 24. After being absorbed by the roots:
- 25. Contained in the plant This is what makes the green color
- 26. What does chlorophyll do besides make the plant green?? When sunlight falls on the plant, the chlorophyll captures the energy in it, and stores it for further use.
- 28. This is combined with the carbon dioxide to produce the food for the plant
- 29. The oxygen is let out through the stomates
- 31. We use the oxygen produced by this to fulfill our oxygen intake to live.
- 32. Proteins Fats Water soluble sugars
- 35. Sunlight, water, and the plants work together to supply the raw source of energy to us and help us breathe in oxygen to live on.
- 36. Life without photosynthesis would be impossible!!!
- 38. UNIT THREE HUMAN EVOLUTION ZANELE PATIENECE NDEBELE 201243373 201243373@STUDENT.UJ.AC.ZA
- 39. What is Evolution? It is the gradual change from one form to another through a period of time.
- 41. Lamarck’s Theory Acquired traits can be inherited He proposed that: Organisms change as their environment changes
- 43. Darwin’s Theory Published “Origin of Species” Traveled around the world in the Beagle He proposed that: Organisms produce more offsprings than the available resources can support Organisms fight for limited resources like food, territory, and other necessities of life. Only those who survive can produce their own offspring
- 44. Variation exists within species. For example, some gorillas have longer arms than others. Natural Selection - The environment selects organisms with beneficial traits. Adaptation
- 45. Adaptation
- 46. Lamarck vs Darwin Jean Baptist de Lamarck Charles Darwin 1809 1859 French Naturalist English Naturalist Acquired traits can be inherited by an organism Organism adapts to changes in the environment. Only the fittest organisms survive through natural selection.
- 48. Gradual change from one form to another through a period of time The environment selects organisms with beneficial traits A form modified to fit a changed environment
- 49. Evidences of Evolution Any preserved part or tissue of an organism that once lived. FOSSIL
- 51. Types of Fossils Casts The mold is filled with another material Molds Imprints Petrified Fossils Hard body structures Feathers and leaves that form impressions on rocks When minerals replace the hard parts of organisms
- 52. Biochemical Evidences DNA Indicate that some organisms have similar DNA sequences, which suggest common ancestry
- 53. VARIATION
- 55. Patterns of Evolution Divergent Related organisms become very different Convergent Distantly related organisms develop similar characteristics
- 59. REFERENCES Shyla Turner *** Instructional Technology TR 9:3010:45*** Isabel V. Neri Ziningi Mthembu (student at university of Johannesburg)