Mutations

Mutation defintion

Mutations are a permanent changes in DNA nucleotide sequences

Where can mutations occur?

In any cell

Scales of mutation

• Chromosomal

• Gene

Why do mutations appear?

• Mutagens

  • Errors in DNA replication

  • Environmental factors

    • UV exposure

    • Chemicals

    • Radiation

Types of mutation

• Point mutations

• Frameshift mutations: changes the reading frame

Point mutations

• Substitutions: swapping of nucleotides in DNA sequence

  • Silent

    • Makes no change to amino acid

  • Missense

    • Changes amino acid

  • Nonsense

    • Creates a premature stop codon

Frameshift mutations

• Deletion

  • Takes amino acid away

• Insertion

  • Adds in extra amino acid

Heredity of Mutations

• Germline

  • Mutations that are heritable

    • DNA sequence changes within gametes

• Somatic

  • Mutations that occur in body cells

    • Not able to be passed down to further generations

Why Mutations Matter

Creates the ability for new functions

Mutations can be…

• Neutral

  • No impact on fitness

• Beneficial

  • Increases fitness of organism

• Harmful

  • Decreases fitness of organism