During fertilisation the haploid nucleus of a sperm cell and the haploid nucleus of an egg cell fuse together to form a diploid zygote.

Gametes are haploid cells, and each cell carries only one copy of each chromosome. These reproductive cells are produced through a type of cell division called meiosis. During meiosis, a diploid ...

The nucleus of a germline stem cell undergoes two divisions, firstly separating homologous chromosomes and secondly separating chromatids. Haploid gametes contain 23 single chromosomes.