Meiosis & Fertilisation

• What do you learn about chromosomes and gametes by the end of the video?

  Meiosis halves chromosomes, gametes are produced
• How many pairs of chromosomes are in a normal human cell?

  23 pairs
• What type of chromosomes do gametes contain?

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

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

  In 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
• How are the gametes produced by meiosis described?

  Genetically different from each other
• What is the significance of fertilization in terms of chromosome number?

  Restores the full number of chromosomes
• What do the fertilized egg cells contain?

  23 chromosome pairs
• What process occurs after fertilization?

  The new cell divides by mitosis
• What is formed as the embryo develops?

  Different cell types
• What are the stages of meiosis?

  • Meiosis occurs in reproductive organs
  • Chromosomes are copied
  • Cell divides into two
  • Each cell divides again
  • Produces four genetically different gametes
• What is the relationship between meiosis and fertilization?

  • Meiosis halves the number of chromosomes
  • Fertilization restores the full number of chromosomes
• What happens to the fertilized egg after fertilization?

  • Divides by mitosis
  • Forms an embryo
  • Cells differentiate into various types
• Briefly describe the results of meiosis

  • 4 gametes are produced
  • Each with only a single set of chromosomes
  • Each of the gametes is genetically different from the others