Meiosis.

Normal body cells have a diploid number of chromosomes, two of each chromosome.

Gametes have a haploid number. There is only one copy of each chromosome.

Cells formed by meiosis are all genetically different, because each new cell has a different combination of chromosomes.

Interphase occurs before meiosis. DNA unravels and replicates so two copies of each chromosome are in the cell.

Each copy is a chromatid. A pair are sister chromatids. Joined with a centromere.

Meiosis 1.

Prophase 1.

*Chromosomes condense, become shorter and fatter.

*Homologous chromosomes pair up.

*Crossing…