The significance of meiosis

• why is meiosis important?

  • it keeps the chromosome number constant from one generation to the next
  • it generates genetic variation in the gametes and therefore the zygotes that they produce
• what are the 2 ways that meiosis generates genetic variation in the gametes and therefore the zygotes that they produce?

  • crossing over during prophase 1
  • independent assortment
• how does independent assortment contribute to generating genetic variation in the gametes and therefore the zygotes that they produce

  • metaphase 1 - so that the daughter cells contain different combinations of maternal and paternal chromosomes
  • metaphase 2 - so daughter cells contain different combinations of chromatids
• why are sources of variation important to species in the long term?

  in the long term, if a species is to survive in a constantly changing environment and to colonise new environments, sources of variation are essential