Meiosis and Fertilisation

• How many pairs of chromosomes are in a normal human cell?

  23 pairs
• What type of cells contain single chromosomes?

  Gametes
• How many single chromosomes does a human gamete contain?

  23 single chromosomes
• Where does meiosis take place in humans?

  Reproductive organs
• What are the male and female reproductive organs called?

  Testes and ovaries
• What happens to chromosomes in the first stage of meiosis?

  All chromosomes are copied
• How many gametes are produced from one original cell in meiosis?

  Four gametes
• What is unique about the gametes produced by meiosis?

  They are genetically different
• What happens to the number of chromosomes during fertilization?

  It is restored to normal
• What do scientists call the joining of male and female gametes?

  Fertilization
• What does a fertilized egg contain in terms of chromosomes?

  23 chromosome pairs
• What process occurs after fertilization?

  Mitosis
• What is formed as a result of mitosis after fertilization?

  An embryo
• What happens to cells as the embryo develops?

  They differentiate into different cell types
• What types of cells are formed during differentiation in animals?

  Nerve cells and muscle cells
• What are the stages of meiosis relevant to the AQ8 specification?

  • Meiosis occurs in reproductive organs
  • Chromosomes are copied
  • Cell divides into two
  • Each cell divides again
  • Four genetically different gametes produced