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Science

Gene control

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Asexual and sexual reproduction

Asexual reproduction

Asexual reproduction only needs one parent. All the offspring are genetically identical to each other, and their parent. They are clones.

Sexual reproduction

Sexual reproduction needs two parents. Each parent produces sex cells, called gametes:

  • male gametes are called sperm
  • female gametes are called eggs

Each gamete contains half the number of chromosomes that a body cell has. At fertilisation, a male and female gamete fuse or join together. The new cell contains the full number of chromosomes.

Half of its genes have come from the father, and half have come from the mother. The genetic material from both parents has combined to form a unique individual.

Higher only

Genetic material is randomly mixed during fertilisation. Any two gametes can randomly meet and fuse, producing a unique combination of genetic information in the offspring.

the female egg and the male sperm fuse to create a zygote cell which then turns into an embryo. 23 chromosomes from the male and female each make 46 chromosomes in 23 pairs

Process of fertilisation

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