Chapter 11 Flashcards
Mutations that occur in germ-line cells, giving rise to sperm and egg, are called __________
germ-line mutations
Cells not in the germ line are called somatic cells; mutations in such cells are called _______
somatic mutations
Germ-line mutations _______ be passed from one generation to the next, while only _______ descendants of the original mutated somatic cell will carry the mutation
can
direct
localized mutations or _______ occur at a specific identifiable position in a gene
point mutation
Genes with elevated mutation rates are called _______
mutation hot spots
What are the 2 different types of base-pair substitution mutations?
1) transitions
2) transversions
What substitution results in transitions?
A to G (vice versa)
C to T (vice versa)
What are the 3 results that can result from a base pair substitution?
1) silent mutation
2) missense mutation
3) nonsense mutation
_______: no amino acid change
silent mutation
_______: changes in amino acid
missense mutation
_______: creates a premature stop codon
nonsense mutation
_______ or _______ of one or more base pairs altering the reading frame of the message
insertion or deletion
insertion or deletion of one or more base pairs that alters the reading frame results in _______
frameshift mutations
Mutations that alter consensus sequence nucleotides of promoters are called _______
promotor mutations
promotor mutations interfere with the efficiency of _______
transcription initiation
Mutations that alter mRNA required for specific sequences at either end of the intron are called _______
splicing mutations
Base-pair substitutions that results in the production of new splice sites that replace or compete with authentic splice sites during mRNA processing are called _______
cryptic splice sites
polyadenylation mutations can _______ proper 3’ processing of mRNA
block
_______: converts a wild type allele to a mutant allele
forward mutation
_______: convert mutant alleles to wild-type or near wild-type
reverse mutations or reversions
_______: wild-type DNA sequence is restored by a second mutation within the SAME codon
true reversion
_______ is reversion that occurs through mutation elsewhere in the same gene
intragenic reversion
_______ occurs by a mutation in a different gene and together the two mutations restore the organism to wild-type
second-site reversion
Second site reversions are also known as _______ because the second mutation “suppresses” the mutant phenotype caused by the first mutation
suppressor mutations