Genetic Variation

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  • Genetic Variation
    • Fertilsation
      • 2) But, fertilisation is a bit random- you don't know which two gametes are going to join together.
      • 1) Fertilisation is when the sperm and egg (with 23 chromosomes each) join together to form a new cell with the full 46 chromosomes.
    • Gamete Formation
      • 3) When these body cells split to form gametes the chromosomes also split up. This means that gametes end up with half the number of chromosomes of a normal body cell- 23.
      • 2) The body cells they're made from hae 23 chromosomes. In each pair there's one chromosome that was inherited from your mother and one from your father.
      • 4) In each gamete some of your dad's chromosomes are linked in with some of your mum's
      • 1) Gametes are sperm cells and egg cells. Gametes are formed in the testes or ovaries.
      • 5) This shuffling up of chromosomes leads to variation in the new generation.
    • Mutations
      • 2) This can create new characteristics, increasing variation.
      • 1) Ocassionally a gene may mutate- this just means that it changes


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