Meiosis

• What type of cell division is meiosis?

  Cell division
• Meiosis produces daughter cells that are genetically different
• Meiosis involves two nuclear divisions.
• How many haploid daughter cells are produced in meiosis?

  Four
• A haploid cell has only one set of chromosomes
• What term describes a cell with two sets of chromosomes?

  Diploid
• Stages of meiosis

  1️⃣ Interphase

  2️⃣ Meiosis I

  3️⃣ Meiosis II
• Interphase is part of meiosis.

  False
• Where do independent segregation and crossing over occur in meiosis?

  Meiosis I
• Homologous chromosomes have the same genes but different alleles
• What happens during independent segregation of homologous chromosomes?

  Random alignment at equator
• The arrangement of homologous chromosomes at the equator is random.
• What is the mathematical formula to calculate the number of possible combinations of chromosomes in gametes due to independent segregation?

  $2^{n}$
• For humans, the number of homologous pairs is 23
• Independent segregation alone creates over 8 million possible combinations of chromosomes in human gametes.
• What happens during crossing over in meiosis?

  Exchange of chromatid sections
• Crossing over occurs between homologous chromatids
• Crossing over results in new combinations of alleles on the chromatids.
• How does crossing over introduce genetic variation?

  Recombination of alleles
• What is the main difference between meiosis and mitosis in terms of chromosome number in daughter cells?

  Haploid in meiosis, diploid in mitosis
• Meiosis results in genetically varied cells, while mitosis results in genetically identical cells.
• Meiosis involves two nuclear divisions, whereas mitosis involves only one.
• What should you look for in a lifecycle diagram to identify where meiosis occurs?

  Diploid to haploid change
• Gametes are always created by meiosis.

  False
• What is the role of fertilization in introducing further genetic variation?

  Random fusion of gametes
• In humans, fertilization results in over 7 x 10^13 possible combinations of chromosomes
• Identical twins are genetically identical because they arise from the same fertilized egg.
• What is the primary purpose of meiosis?

  Introduce genetic variation