Inheritance, Variation and Evolution

• What are the two types of reproduction discussed?

  Sexual and asexual reproduction
• How many pairs of chromosomes do human cells contain?

  23 pairs of chromosomes
• What process do cells undergo to divide into two identical cells?

  Mitosis
• What are gametes in humans?

  Sperm cells and egg cells
• How many chromosomes do human gametes contain?

  23 single chromosomes
• What type of cell division produces gametes?

  Meiosis
• How do the cells produced by meiosis differ from those produced by mitosis?

  Meiosis produces non-identical cells
• What are the gametes in flowering plants?

  Pollen and egg cells
• What is the key feature of sexual reproduction?

  Fusion of male and female gametes
• What is the term for the joining of gametes in sexual reproduction?

  Fertilization
• What does sexual reproduction lead to in offspring?

  Variation in genetic information
• What is an example of asexual reproduction shown in the material?

  Aphid reproducing alone
• How many parents are involved in asexual reproduction?

  One parent
• What are the offspring of asexual reproduction called?

  Clones
• What type of cell division occurs in asexual reproduction?

  Mitosis
• How does the plant reproduce in the example given?

  By forming tiny buds
• What is the genetic relationship between offspring and parent in asexual reproduction?

  Offspring are genetically identical
• What are the main differences between sexual and asexual reproduction?

  • Sexual reproduction involves two parents and gametes.
  • Asexual reproduction involves one parent and no gametes.
  • Sexual reproduction leads to genetic variation.
  • Asexual reproduction produces genetically identical clones.
• What are the key processes involved in sexual and asexual reproduction?

  • Sexual reproduction: Fertilization, meiosis
  • Asexual reproduction: Mitosis
• What are the implications of genetic variation in offspring?

  • Variation allows adaptation to environments.
  • Increases survival chances of species.
• What types of organisms perform sexual and asexual reproduction?

  • Sexual reproduction: Animals and flowering plants
  • Asexual reproduction: Many single-celled organisms and some plants
• What process produces gametes in humans?

  Meiosis
• 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 are in a human gamete?

  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
• Are the gametes produced by meiosis genetically identical?

  No, they are genetically different
• What is the term for the joining of male and female gametes?

  Fertilization
• What happens to the number of chromosomes after fertilization?

  It is restored to normal
• How many chromosome pairs does a fertilized egg contain?

  23 chromosome pairs
• What process occurs after fertilization in the new cell?

  It divides by mitosis
• What is formed as the embryo develops?

  Different cell types
• What types of cells are included in animal differentiation?

  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
  • Produces four genetically different gametes
• What are the key concepts of meiosis and fertilization?

  • Meiosis halves chromosome number
  • Gametes contain single chromosomes
  • Fertilization restores full chromosome number
  • Embryo develops through mitosis
• What should you be able to describe after this video?

  Advantages and disadvantages of reproduction
• What types of reproduction can some organisms use depending on circumstances?

  Both sexual and asexual reproduction