meiosis

• What must occur before the first division in Meiosis?

  Interphase
• What happens during Interphase in Meiosis?

  DNA is replicated
• At which stage does 'crossing over' occur in Meiosis?

  Prophase 1
• What is the purpose of 'crossing over' in Meiosis?


  To increase genetic variation
• What occurs during Metaphase 1 of Meiosis?

  Independent assortment
• How do homologous chromosomes align during Metaphase 1?

  Randomly along the equator
• What is the effect of independent assortment in Metaphase 1?


  It increases genetic variation
• What does Cytokinesis 1 produce in Meiosis?


  Two diploid cells
• What occurs during Metaphase 2 of Meiosis?

  Independent assortment
• How do chromosomes align during Metaphase 2?

  Randomly along the equator
• What is the effect of independent assortment in Metaphase 2?

  It increases genetic variation
• What does Cytokinesis 2 produce in Meiosis?


  Four haploid cells
• How are the new haploid cells produced in Meiosis related to each other?

  They are genetically different
• What are the key stages of Meiosis and their functions?

  • Interphase: DNA replication
  • Prophase 1: Crossing over occurs
  • Metaphase 1: Independent assortment of homologous chromosomes
  • Cytokinesis 1: Produces two diploid cells
  • Metaphase 2: Independent assortment of chromosomes
  • Cytokinesis 2: Produces four haploid cells
• What are the main processes that increase genetic variation in Meiosis?

  • Crossing over during Prophase 1
  • Independent assortment during Metaphase 1 and Metaphase 2
• what is a diploid (2n)?

  Total number of chromosomes in a somatic cell
• what is a haploid (n)?

  total number of chromosomes in a gamete
• what is an allele?


  different form of the same gene
• what are homologous chromosomes?


  chromosomes = same size, shape + carry same genes

  may carry different alleles

  1 chromosome of each homologous pair comes from each parent (in humans)
• what is a polploidy?


  an organism that has more than 2 sets of chromosomes