Here's why:
* Egg cells are produced by the female reproductive system through a process called oogenesis. They contain half the number of chromosomes from the mother's full set.
* Sperm cells, on the other hand, are produced by the male reproductive system through spermatogenesis. They also contain half the number of chromosomes, but these are from the father.
During fertilization, the egg cell and sperm cell fuse, combining their genetic material to create a zygote. This zygote inherits half of its chromosomes from the mother (via the egg cell) and half from the father (via the sperm cell).
