gene mutations Flashcards
what is a mutation
- an alteration to the DNA base sequence
- often arises spontaneously during DNA replication
what are addition and deletion mutations
one or more nucleotide are either inserted or deleted from the DNA sequence
what is a substitution
where one nucleotide in the DNA sequence is replace by another
what is a duplication
where one or more nucleotides duplicate and repeat
what is an inversion
where a group of nucleotide become separated from the DNA sequence, then re-join in reverse order
what is a translocation mutation
where a group of nucleotides become separated from the DNA sequence and are then inserted into the DNA of a different chromosomes
which mutation is most likely to have the most significant impact and why
- insertion, deletion, duplication and translocation
- produce a frameshift meaning the entire amino acids sequence produced will be different
- resulting in a non functional protein
which mutations are less likely to have significant impact
- substitution and inversion
- genetic code is degenerate so amino acid sequence may not be affected
is a mutations that changes the amino acid sequence always harmful
no
- may be a neutral if change in protein has no effect on individual
- may be beneficial on the basis for evolution and natural selection
what is a mutagenic agent
factors that increase the rate of gene mutation
