Genetic variation

A genetic mutation is a change to one or more nucleotide bases in the base sequence of DNA which results in the formation of a new allele They can arise spontaneously during DNA replication

Substitution, Deletion and insertion

One base is replaced (No frameshift)

One base is lost resulting in a frameshift

A base is added resulting in a frameshift

Silent , nonsense and missense

No change in amino acid sequence due to degenerate code

Results in formation of a stop protein level codon

Results in a formation of a different amino acid

1) A missense mutation is a result of a new amino acid 2) This amino acid changes the primary structure which changes the tertiary structure as bonds are in different places 3) This changes the shape of the enzymes active site 4)Enzymes active site and substrate are no longer complementary and cant form an enzyme-substrate complex

A result of Non-disjunction which is when changes can occur in whole new sets of chromosomes so that an individual has three of more sets of chromosomes instead of two

When chromosomes fail to separate in meiosis I or chromatids fail to separate in meiosis I so gametes will could have one more or one less chromosome then they should ( Causes genetic variation )

Increases the rate of mutation E.G UV radiation, Smoking, Carcinogen, X-ray

The random fusion of gametes creates random allele combinations