Genetic Diversity: Mutations & Meiosis

• Deletion mutation


  • When a nucleotide in the DNA sequence is lost
  • This is more likely harmful as it leads to a frame shift which means the entire amino acid sequence will be different
• Substitution mutation


  • When a nucleotide in the DNA sequence is replaced by another
  • Likely to be a quiet mutation meaning no change occurs in the amino acid sequence
• Define mutagenic agent

  Factors that increase the rate of gene mutation e.g X rays, UV light, Gamma rays
• Meiosis

  A type of cell division that produces daughter cells which are genetically different
• Haploid cells


  • Have one set of chromosomes
• Diploid cells


  • Have two sets of chromosomes
• Independent segregation

  Homologous chromosomes line up randomly at the equator during meiosis I, resulting in random distribution to daughter cells
• Causes of genetic variation

  • Genetic Mutations
  • Crossing over
  • Independent segregation
  • Random fusion of gametes