Mutations Any change in an organism’s DNA. Mutations in somatic cells only impact individual; mutations in gametes may impact offspring. 2 Types: A. Gene Mutations- involves nucleotide B. Chromosomal Mutations- involves pieces of genes or entire chromosomes.

Gene Mutations Point Mutation- one nucleotide is SUBSTITUTED for another. If a substitution changes the amino acid, it’s called a MISSENSE mutation. If a substitution does not change the amino acid, it’s called a SILENT mutation. If a substitution changes the amino acid to a “stop,” it’s called a NONSENSE mutation.

Substitution Point/Subsitution (one base is substituted for another) If a substitution changes the amino acid, it’s called a MISSENSE mutation. If a substitution does not change the amino acid, it’s called a SILENT mutation. If a substitution changes the amino acid to a “stop,” it’s called a NONSENSE mutation.

2. Frameshift Mutation- nucleotide is INSERTED or DELETED. Changes the entire A.A. sequence

Chromosomal Mutations Affect several genes and have a huge impact on organism. 1. 2. 3. 4.

II. Chromosomal Mutations Mutations involving changes in large regions of chromosomes 4 Types: 1. Deletions- part of chromosome is left out

II. Chromosomal Mutations 2. Insertions- part of chromatid breaks off and attaches to sister chromatid resulting in duplication of genes on some chromosomes

II. Chromosomal Mutations 3. Inversions- part of chromosome breaks off and is reinserted backwards

II. Chromosomal Mutations 4. Translocations- part of one chromosome breaks off and is added to a different chromosome