Chapter 18 Flashcards
1
Q
Importance of mutations
A
- sustainer of life and cause of great suffering
- useful for probing fundamental biological processes
2
Q
Somatic mutations
A
- occurs in non-reproductive cells
- passed to new cells through mitosis
- creating a clone of cells having the mutant gene
3
Q
Germ-line mutation
A
- occurs in cells that give rise to gametes
- meiosis and sexual reproduction
- all cells carry
4
Q
Mutations
A
- Inherited alterations in the DNA sequence
5
Q
Types of gene mutations
A
- Base substitutions
- insertions
- deletions
6
Q
Base substitutions (transition)
A
- substitution of a purine for a purine or of a pyrimidine for a pyrimidine
7
Q
Base substitution (transversion)
A
- substitution of a pyrimidine for a purine or of a purine for a pyrimidine
8
Q
Insertions and deletions
A
- frameshift
- In-frame insertions and deletions
9
Q
Expanding nucleotide repeats
A
- Increase in the number of a copies of a set of nucleotides
10
Q
Diseases caused by expanding nucleotide repeats
A
- Huntington disease
- Jacobsen syndrome
- Myotonic dystrophy
11
Q
Forward Mutation
A
- wild type to mutant type
12
Q
Reverse mutation
A
- Mutant type to wild type
13
Q
Missense mutation
A
- amino acid to different amino acid
14
Q
Nonsense mutation
A
- sense codon to nonsense codon
15
Q
Silent mutation
A
- codon to synonymous codon
16
Q
Neutral mutation
A
- no change in function
17
Q
Loss of function mutations
A
- loss of function
18
Q
Gain of function mutation
A
- Gain of activities
19
Q
Phenotypic effects of mutations
A
- loss of function
-gain of function - conditional
- lethal
20
Q
Supressor mutation
A
- hides or suppresses the effect of another mutation
- intragenic
- intergenic
21
Q
Intragenic suppressor
A
- occurs in the gene containing the mutation being suppressed
22
Q
Intragenic suppressor
A
- occurs in a gene other than the one bearing the original mutation
23
Q
Forward mutation
A
- wild type to mutant phenotype
24
Q
Reverse mutation
A
- mutant phenotype back to wild type phenotype
25
Q
Causes of mutation
A
- UV
- Gamma Rays
- Tobacco
26
Q
Transposable elements
A
- sequences that can move about the genome
- Also known as “jumping genes”
27
Q
Transposable elements cause mutations by
A
- inserting into another gene
- promoting DNA rearrangements
- EX. color of grapes & human genetic diseases
28
Q
Barbara McClintock
A
- discovered transposable elements
29
Q
Mismatch
A
- DNA repair mechanism
- replication error
30
Q
Direct repair
A
- DNA repair mechanism
- pyrimidine dimers
31
Q
Base- excision repair
A
- DNA repair mechanism
- abnormal bases
32
Q
Nucleotide-excision repair
A
- DNA repair mechanism
- DNA damage that distorts the double helix
