Where does fertilisation occur in humans? Explain the events that occur during this process
In humans, the fertilisation of ovum takes place in ampullary-isthmic junction of Fallopian tube.
The events that occur during the process of fertilisation are:
(i) The sperm reaches the junction of ampulla and isthmus and comes in contact with zona pellucida layer of ovum.
(ii) Acrosome of sperm head release sperm lysin enzymes that dissolves corona radiata and digests zona pellucida layer and enters cytoplasm.
(iii) Entry of sperm stimulates secondary oocyte to complete its suspended second meiotic division, thus producing haploid egg or ovum and second polar body.
(iv)Nucleus of sperm and of ovum fuses to form a diploid zygote.