Point Mutations and Chromosomal Mutations

Point Mutation

A change of a single nucleotide

Silent Mutation

A mutation that has no effect on a gene's function

Missense Mutation

A mutation that causes the codon to code for a different amino acid

Nonsense Mutation

A mutation that causes a codon to change to a STOP codon

Frameshift Mutation

A mutation that causes a shift in the reading frame

Insertion

Adding one or more nucleotides

Deletion

Removing one or more nucleotides

Gene mutation

Affects one gene

Chromosomal mutation

Affects many genes

Mutant

An individual whose DNA or chromosomes are different

Deletion

A piece of chromosome is lost

Duplication

Both pieces remain attached to the same homologous chromosome

Inversion

A piece of patches in the opposite direction

Translocation

A piece ends up on a completely different chromosome

Nondisjunction

Occurs when homologous chromosomes fail to separate

Gene rearrangement

An entire gene is moved to another location

Substitution

Changing a single nucleotide to another nucleotide