Genetics

- Gene mutations also called point mutations
- Base substitution – those mutations in which one base pair is replaced by another.
o Transition – the replacement of a base by the other base of the same chemical category (A to G, G to A, C to T, T to C). Base pair changes would be: G.C to A.T
o Transversion – the replacement of a base of one chemical category by a base of the other (purine to pyrimidine, pyrimidine to purine). Base pair changes would be: G.C to T.A
- Addition or deletion mutation – occur in pairs (base pair additions or deletions). Result in frameshift mutations, which cause the entire amino acid sequence translationally downstream of the mutant site to bear no relation to the original amino acid sequence. Typically exhibit complete loss of normal protein structure and function.
o Silent substitutions – the mutation changes one codon for an amino acid into another codon for that same amino acid. Never alter the amino acid ...