Formation of zygote is universal in all sexual reproducing organism. Zygote is the first product of sexual reproduction which is formed by fusion of male gamete with egg cell or female gamete. Zygote undergoes cleavage which reduces the cell size. Every sexually reproducing organism, including human beings begin life as a single cell the zygote. Zygote is the vital link between organism of one generation and next as it undergoes division to form embryo from which new progeny develops.