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Biology · Paper 2 · Foundation + Higher · B6

Meiosis and fertilisation

Key ideas1 of 3

Copy once, divide twice

Before meiosis, the cell copies its DNA. It then divides twice, producing four gametes. Each gamete has one set of chromosomes, half the number in the starting cell. The gametes have different combinations of genetic information.

Start with two homologous chromosome pairs.

Next: DNA, genes and the genome →
Practice, downloads and sources

Daily 5 · Exam practice · Revision sheet ↓

Foundation + Higher · B6. Fourteen core lessons, followed by two labelled Higher Tier lessons.

AQA Combined Science Trilogy 8464 · 4.6.1.2. Original notes, questions and diagrams. Models are simplified; teaching data are illustrative.