A biological process in which the fusion of the male and the female gamete occurs is called fertilization. The sperms are released from the male reproductive organ called the penis. The sperm enters the female body through one of the parts of her reproductive organ called the vagina. Then the sperm travels through the fallopian tubes and meets the egg produced by the female organs. The process of fertilization takes place in fallopian tubes. When the male and female gametes fuse the first cell formed is called zygote. The whole process takes place inside the female body hence it is called internal fertilisation. In this manner zygote is formed internally.