The fusion of male gamete(sperm) with female gamete(egg)give rise to a new cell called zygote. The new cell which is formed by the fusion of a male gamete and female gamete is called zygote(fertilised egg) Zygote is a single cell which contain one nucleus.The nucleus of zygote is formed by the combination of nuclei of sperm and egg. The fusion of male gamete with a female gamete to form a zygote during sexual reproduction is called fertilisation. Many sperms try to enter the egg, only one sperm is successful in entering the egg.When the head of sperm enters the egg, then the nucleus of sperm cells fuses with the nucleus of egg cell to form a new nucleus.This results in the formation of fertilised egg or zygote. All the multicellular animals start their life from a single cell called zygote. The fertilisation of an egg by sperm can take place either inside the body of female or outside the body of female animal.

When the male sperm and female egg fuse new cell is formed called zygote

Zygote is a cell formed by the union of a male sex cell (sperm) and female sex cell (ovum). this zygote can also be called as egg, which later devlop into embryo