Single nucleotide variation. Small but have a significant effect on phenotype if occurring in the exon of a gene or intron where gene expression is affected
Effect: named to how they change nucleotide sequence of dna→ effects expression of mutated genes. Result in base substitution or frameshift mutation
Base substitution: one nucleotide base replaced by a different base→ different amino acid being inserted in the polypeptide.
Sickle cell gene: human red blood cells cause anemia. CTC changed to CAC causing missense mutation (phenotypic effect). This causes amino acid glutamate to be swapped for valine altering shape of the hemoglobin molecule and resulting in sickle cell shape
Change in amino acid in protein changes the function of protein
