Classification of Gene Mutations Flashcards
what would there not be without variation from mutations
no phenotypic variability
no adaption to environmental change
no evolution
e.g of what bad things mutations can lead to
cell death
genetic diseases
cancer
what would be impossible without mutations
genetic analysis
what’s a mutation
the alteration in nucleotide sequence of an organism’s genome
3 things a mutation might be
single base-pair substitution
deletion
insertion of 1/more base pairs
e.gs of non coding regions where mutations may occur
introns
promoters
enhancers
splicing signals
how do mutations get in germ cells
inherited
what do germ cell mutations cause
genetic diversity
evolution
genetic disease
what cells don’t carry heritable mutations
somatic cells
5 main types of mutations
point mutation/ base substitution missense mutation nonsense mutation silent mutation Frameshift mutation
what is a point mutation
change of 1 base to another (base substitution)
what’s a missense mutation
change of 1 nucleotide of a triplet in a protein-coding part of gene
what is a triplet changed into in nonsense mutations
a stop codon
describe a silent mutation
point mutation alters a codon but doesn’t cause an Amino acid change
why are most mutations in eukaryotes neutral mutations
as genomes contain a lot more non coding DNA
what’s transition a point mutation base change in
pyrimidine replaces pyrimidine
purine replaces purine
what happens in a transversion
purine replaces pyrmidine + vice versa
what are frameshift mutations
the insertion/deletion of 1/more nucleotides at any point in a gene
what do frameshift mutations cause to change
all subsequent 3 letter codons
what codon can terminate polypeptide synthesis (one of many altered triplets)
translation termination codon
what can frameshift mutations produce
a truncated protein/ defective enzymes
