Genetic mutations

Mutations

DNA Overview

  • The sequence of DNA determines an animal's phenotype.

  • DNA is composed of 4 letters and has 64 possible 3-letter combinations.

  • Mutations are errors in DNA replication.

Point Mutation

  • A single nucleotide base is changed, inserted, or deleted.

  • Effects can range from no impact (synonymous mutations) to harmful (frameshift mutations).

Types of Mutations

  • Insertion: Adds extra nucleotides.

  • Deletion: Removes nucleotides.

  • Duplication: Copies a gene or chromosome region.

  • Translocations: Chromosome segments change positions.

  • Frameshift: Alters reading frame due to insertions/deletions.

  • Nonsense Mutation: Introduces a premature stop codon.

  • Missense Mutation: Results in a different amino acid within the protein.

  • Neutral Mutation: Change with no effect on survival and reproduction.

  • Silent Mutation: A specific neutral mutation with no observable effect on phenotype.

Effects of Mutations

  • Effects of mutations can be beneficial, neutral, or harmful.

  • Most mutations are neutral and do not affect the organism (e.g., silent point mutations).

  • Beneficial mutations contribute to adaptation and are crucial for evolution.

  • Harmful mutations can disrupt normal protein function, leading to genetic disorders or cancer.