Chapter 13 Flashcards
(57 cards)
3 important consequences of mutations
1) Source of all genetic variation, which further provides the raw material for evolution
2) Source of many diseases and disorders
3) Useful for probing fundamental biological processes
Consequence of somatic mutation
the mutation is passed to new cells through mitosis, creating a clone of cells w/ mutant gene
Consequence of germ-line mutation
1/2 the members of the next generation carry the mutation in all their cells
What’s a transition mutation
Transitions are base substitutions in which purines are replaced by purines or pyrimidines are replaced by pyrimidines.
What are transversion mutations
Transversions are base substitutions in which a purine replaces a pyrimidine or a pyrimidine replaces a purine.
What are the consequences of insertion/deletion mutations
1) Frameshift mutations
2) In-frame insertions and deletions
What are transition and transversion categorized as
base substitutions
What’s the result of a missense mutation
A missense mutation alters the one nucleotide in the coding sequence so that one amino acid is substituted for another.
Result of nonsense mutation
A nonsense mutation changes a codon that specifies an amino acid into a stop codon.
Result of silent mutation
A silent mutation produces a synonymous codon that specifies the same amino acid as the original sequence, whereas a neutral mutation alters the amino acid sequence but does not change the functioning of the protein.
What’s forward mutation
wild type to mutant type mutation
What’s a reverse mutation
mutant type to wild type mutation (restores the wild-type )
4 phenotypic effects of mutations
1) Loss-of-function mutation
2) Gain-of-function mutation
3) Conditional mutation
4) Lethal mutation
What’s a suppressor mutation
a mutation that hides or suppresses the effect of another mutation
T/F: Suppressor mutation occurs at the same site as the original mutation
F: it occurs at a different site than the original mutation
What’s an intragenic mutation
intragenic (within the same gene as the original mutation)
What’s an intergenic mutation
Suppressor mutation within a different gene than the one originally affected
What’s a loss-of-function mutation
causes complete or partial loss of function
what’s a gain-of-function mutation
causes the appearance of a new trait or function or causes the appearance of a trait in inappropriate tissue pr at an inappropriate time
What are some other ways that mutations can occur
Spontaneous replication errors
Spontaneous chemical changes
Chemically induced mutations
Radiation
What are transposable elements
Transposable elements are mobile DNA sequences that insert into many locations within a genome and often cause mutations and DNA rearrangements.
What do base analogs do
Base analogs can become incorporated into DNA in the course of replication and pair with the wrong base (through wobble) in subsequent replication events.
What do alkylating agents do
donate alkyl groups
What do alkylating agents, deaminating chemica;s and hydroxylamine do?
Alkylating agents, deaminating chemicals, and hydroxylamine lead to mutations by modifying the chemical structure of bases.
