STANDARD: SC.912.L.16.4
Students will be able to:
- Explain how mutations in DNA sequence may or may not result in phenotypic change.
- Explain how mutations in gametes may result in phenotypic changes in offspring.
Students will be able to:
- Explain how mutations in DNA sequence may or may not result in phenotypic change.
- Explain how mutations in gametes may result in phenotypic changes in offspring.
Student Assignments
- Reading Section Textbook Pages
- Tutorial
- Mutations Power Point
- Mutations Notes Sheet
Mutations are changes in an individual's genetic material.
They can occur in:
- can lead to cancer- like skin cancer
- Can cause cancer family syndrome
-These are more notable, because they introduce genetic diversity and possible phenotypic changes in the population
- Somatic cells (Body cells)
- can lead to cancer- like skin cancer
- Gametes (Sex cells- egg and sperm)
- Can cause cancer family syndrome
-These are more notable, because they introduce genetic diversity and possible phenotypic changes in the population
Cells can sometimes repair the damage, but when they can’t, the DNA sequence changes permanently.
Causes of Mutations
Spontaneous Mutations (natural)
Spontaneous mutations can occur during genetic processes such as
Proof-reading mechanisms often prevent most mutation from happening in DNA Replication, but they are less effective during transcription (production of mRNA) |
Induced Mutations (caused by mutagens)
- Some natural plant alkaloids - Tobacco smoke - Environmental pollutants
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What are the types of mutations?
Mutations can be classified according to the level where the mutation takes place in:
- Gene Mutations: Changes in a single base pair of a gene, also called point mutations
- Chromosomal Mutations: Involves a change in the structure, or the number of chromosomes
What Is a Gene? Revisiting the Question
- A discrete unit of inheritance
- A region of specific nucleotide sequence in a chromosome
- A DNA sequence that codes for a specific polypeptide chain
Gene Mutations are also known as Point Mutations
It is a change in a single base pair of a gene, also called point mutations.
Point mutations within a gene can be divided into two general categories
- or deletions
Point mutations within a gene can be divided into two general categories
- Nucleotide-pair substitutions
- Frameshift Mutations
- or deletions
Gene Mutations: SubstitutionA nucleotide-pair substitution replaces one nucleotide and its partner with another pair of nucleotides.
There are 3 types of substitution mutations:
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Frameshift MutationsThese happen when there are either insertions or deleted nucleotides within the DNA. These include:
Both of these mutations have a disastrous effect on the resulting protein more often than substitutions do, because Insertion or deletion of nucleotides may alter the reading frame, producing a frameshift mutation. |
What impact do mutations pose to health?
- Mutations of genes, chromosome number or chromosome structure may cause some genetic disorders.
- Large-scale chromosomal alterations often lead to spontaneous abortions or cause a variety of developmental disorders