Human Characteristics (B1)

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  • Created by: caits
  • Created on: 17-03-14 17:16

Sexual reproduction causes variation

Gametes contain only 23 chromosomes.They contain 1 of each chromosome type but the way they get split up is random. 

Chromosomes swap pieces of DNA with each other when they pair u during cell division. This increases variation.

Fertilisation:

Every egg and sperm is genentically unique.

The joining of an egg with one of millions of sperm is random.

Sex Chromosomes:

Women - XX

Men - XY

The ratio of baby girls to baby…

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