Gametes are reproductive cells that unite at fertilization and create a new being: the zygote. The female gamete is what we know as egg cell, ovum or oocyte; the male gamete is the sperm or spermatozoon.
Gametes are haploid cells, while the zygote is a diploid cell: while the former has just one complete set of chromosomes, the latter contains two complete sets. Another difference is that diploid cells reproduce by mitosis, while haploids do so by meiosis.
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