Explanation:
Gametes are your sex cells.
Female gametes are the eggs (ovum) and male gametes are the sperm. Each contain 23 chromosomes and are haploid.
During fertilization, the ovum and sperm combine. Only one of each (1 egg, 1 sperm), so that the resulting zygote has 46 chromosomes (23+23) and is considered diploid.
The zygote then undergoes mitosis.