DNA from one generation is passed to the next by gametes
- Gametes are the sperm cells in the males and egg cells in females. They join together at fertilisation to form a zygote, which divides and develops into a new organism.
- Normal body cells have the diploid number (2n) of chromosomes - meaning each cell contains two of each chromosome, one from the mum and one from the dad.
- Gametes have a haploid (n) number of chromosomes - theres only one copy of each chromosomes
- A fertilisation, a haploid sperm fuses with a haploid egg, making a cell with the normal diploid number of chromosomes. Half these chromosomes are from the father and half from the mother.
Gametes are formed by meiosis
- The DNA unravels and replicates so there are two copies of each chromosome, called chromatids.
- The DNA condenses to form double armed chromosomes, made from two sister chromatids
- Meiosis 1 (first division…