This is lesson about Mutation in science 10
- 2. At the end of the lesson the learner will able to: a) Define what is mutation; b)Identify the two categories of mutations. c) Make an essay regarding the advantage and disadvantages of mutations.
- 7. WHAT IS MUTATION? • mutations are changes made to an orgasnism’s genetic material. • changes may be due to errors in replication, errors during transcription, radiation, viruses and many other things.
- 8. IS MUTATION CAN BE GOOD AND BAD?
- 9. Three types of substitution mutation • Nonsense mutation results in the formation of a stop codon due to the substitution of one nitrogenous base. Remember, stop codons are special nitrogenous bases that stop the translation stage in protein synthesis.
- 10. Three types of substitution mutation • When one nitrogenous base of the DNA is replaced and the result is an altered codon but does not form a stop codon, it is classified as missense mutation.
- 11. Three types of substitution mutation • Silent mutation happens when a nitrogenous base is altered but the same amino acid is produced. Remember, many codons can code for the same amino acid.
- 12. MUTAGENS- are agents that cause alteration in the DNA and can lead to permanent mutations in the DNA sequence depending on the ability of an organism to repair the damage. Example: Toxic chemicals, harmful radiation, and infectious agents.
- 13. TWO MAJOR CATEGORIES OF MUTATIONS: Germline Mutations- Germline Mutations occur in gametes. These mutations are especially significant because they can be transmitted to offspring and every cell in the offspring will have the mutation. Somatic Mutations- Somatic mutations occur in other cells of the body. These mutations may have little effect on the organism because they are confined to just one cell and its daughter cells. Somatic mutations cannot be passed on to offspring.
- 14. Some mutations in the body cells known to cause cancer. While mutations in reproductive cells cause birth defects and if the mutation is severe, embryo may not be developing.
- 15. 3 TYPES OF GENE MUTATIONS: • BASE SUBSTITUTION- the simplest type of gene mutation because only one base in the sequence is substituted/replace by another, so only one codon is affected. • DELETION- there is one or more base deleted in the sequence. A deletion of one or more codons results in a protein missing one or more amino acids. • INSERTION- happened when a base is added in the sequence.
- 16. CHROMOSOMAL MUTATIONS • Chromosomal alterations are mutations that change chromosome structure. Normally, Zygote carries 46 chromosomes, 23 chromosomes from the sperm cell and 23 from the egg cell. Any excess or lack of this number may result to changes in structure and function of a protein. In most cases these problems may cause problems in the development and function of the body system.
- 17. CHROMOSOMES MUTATE • Deletion- happens when a base is deleted from the nitrogen base sequence • Duplication- occurs when a part of a chromosome is copied (duplicated) too many times. This type of chromosomal change results in extra copies of genetic material from the duplicated segment.
- 18. CHROMOSOMES MUTATE • Translocation- segments of two chromosomes are exchanged. • Inversion -happens when a part of a single chromosome breaks and rearranges itself in reversed. • Insertion- the addition of one or more nucleotide base pairs into a DNA sequence.
- 19. GENETIC DISORDER CAUSE CHARACTERISTICS/EFFECT “cri-du-chat” or Cat`s Cry syndrome Deletion of part of the short arm of chromosome 5 High-pitched cries that sound like a cat, a small head and jaw wide-set eyes, very short and moderately to severely mentally retarded Down`s syndrome Extra copy of chromosome 21 Stockier build, decreased muscle tone, asymmetrical skull, slanting eyes and mild to moderate mental retardation. Edwards`s syndrome Trisomy of chromosome 18 presence of extra copy of the genetic material Mental and motor retardation and numerous congenital anomalies causing health problems Jacobsen Syndrome Deletion of genetic material chromosome 11 Normal intelligence or mild retardation, with poor or excessive language skills, bleeding disorder.
- 23. DOWN’S SYNDROME
- 24. SUMMARY! • Some mutations have a positive effect on the organism in which they occur. They are called beneficial mutations. They lead to new versions of proteins that help organisms adapt to changes in their environment. Beneficial mutations are essential for evolution to occur. They increase an organism’s changes of surviving or reproducing, so they are likely to become more common over time. • Harmful mutations may cause genetic disorders or cancer.
- 25. ACTIVITY TIME! • 1-2 Give the two major categories of mutation. • 3-5 Give the three types of gene mutation • 6-9 Give the four types of Chromosomal mutation • 10 Give at least one chromosomal disorder
Editor's Notes
- #8: MUTATIONS ARE THE RESULTS OF FAILING TO COPY THE CORRECT DNA SEQUENCE DURING REPLICATION
- #9: Yes they can be good or bad for the bad mutations the lead to diseases like cancer or chronic disease on the other hand the good mutations it can allow organism readily adapt to its environemnt
- #14: SOMATIC NOT PASSED FROM PARENTS TO CHILDREN, PARENTS HAVE IT BUT IT AFFECTS ONLY THE CHILDREN THEY HAVE