Biology (A-Level)/Meiosis

This will teach the process of meiosis to A-Level. Specifically, that of the 2008 AQA specification.

Definitions

• Homologous chromosomes — chromosomes that contain the same genes.
• Maternal homologues — chromosomes from the original female parent.
• Paternal homologues — chromosomes from the original male parent.
• The diagram shows a chromosome.
• Each of the strands is a chromatid.
• Chromosomal crossover — the process by which two chromosomes pair up and exchange sections of their DNA.

Stages of meiosis

• Prophase I — Homologous pairs of chromosomes in a diploid cell pair up forming bivalents. Chromosomal crossover occurs.
• Metaphase I — Bivalents line across equator of the spindle opposite homolguos pair of chromosomes.
• Anaphase I —
• Telophase I —
• Interphase —
• Prophase II —
• Metaphase II —
• Anaphase II —
• Telophase II —