gene mutations involve a change in the DNA base sequence of chromosomes
substitution mutation - one base is substituted with another
deletion mutation - one base is deleted
the order of DNA bases in a gene determines the order of amino acids in a particular protein. if a mutation occurs, the sequence of amino acids it codes for (and protein created) could be altered
degenerate nature of genetic code means some amino acids are coded for by multipleDNAtriplets, so not all substitution mutations have an effect as they'll still code for sameaminoacid
deletion mutations always lead to changes in the amino acid sequence - changes number of bases so shifts all basetriplets after it
mutagensincrease the rate of mutation - ultraviolet radiation, ionising radiation, and some chemicals
mutations can occur randomly, ie. when DNA is misread in replication