How does fertilisation take place? Fertilisation occurs once in a month. Comment.

The fusion of male gamete (sperm) with the female gamete (ova) is known as fertilisation. The process of fertilisation takes place in the fallopian tube. As sperm enter into the vagina through the process of copulation; it moves upwards and enter into the oviduct. In the oviduct, ovum fuse with the sperm to form zygote. Numerous sperms reach the fallopian tube but only one sperm is required for fertilization.

The zygote (fertilised egg) get implanted in the inner lining of uterus and undergoes repeated division forming an embryo.

This process occurs once in a month in humans because ovary releases egg (ovulation) once every month.