Question

Fertilization is a process that requires a variety of very specific things to happen. Discuss fertilization in terms of

i) Location

ii) Prevention of polyspermy

iii) Production of ova

iv) Production of semen that contains viable sperm

*do not worry about how Mr Sperm gets toMrs Egg"

Answer 1

I. Location of fertilization:

It is done in the ampulla of fallopian tube, possess a structure namely fimbriae which collects the ova or egg released from ovary. This part of Fallopian tube collects the egg and sperms are travelled a long journey upto the tube and finally fertilze the egg and results in the production of zygote which continues to divide and made blastula and later moves to the Uterus where cells get implanted for future development till embryo.

II. Inside the ova there are sodium ( Na+) channels which shutters in the plasma membrane located below layer of the jelly coat or the vitelline layer. When the conditions are normal Na+ concentration is much higher outside the cell than inside the cell. This leads to the movement of Na+ ions flow down their gradient into the egg and the plasma membrane. This resulted in the depolarization which means positive charges neutralize the more negative charge internally the cytoplasm of the ova. This depolarization causes the prevention of Polyspermy (fusion of more than one sperm with the egg).

III and iv are explained by the diagram:

This shows how the ova and sperms are produced by oogonium and spermatogonium respectively.

uhn thaton ooryte to Fiyst Cotids Ovum Semen