INTRODUCTION OF FERTILIZATION

Question 1

What is the fertilization ?

Answer 1

It is the fusion of the sperm cell nucleus with the egg cell nucleus to produce a zygote .

Question 2

What are the stages of the Fertilization ?

Answer 2

✷ CAPACITATION - activation of the sperm occurs in the uterus and oviducts and is facilitated by substance of the female genital tract.

✷ ACROSOMAL REACTION - fusion of the sperm plasma membrane and the external acrosomal membrane occur. [ The acrosome reaction is associated with the release of acrosome enzymes that facilitate fertilization.

✷ PENETRATION OF THE ZONA PELLUCIDA AROUND THE OOCYTE - Once sperm penetrate the zona pullucida , the zona reaction occurs [ This reaction makes the zone pellucida.

✷ FUSION OF PLASMA MEMBRANES OF OOCYTE AND SPERM

✷ 2ND MEIOTIC DIVISION OF OOCYTE IS COMPLETED.

✷ FORMATION OF THE MALE AND FEMALE PRONUCLEI - Chromosomal material of the sperm decondensates and enlarged.

✷ MEMBRANES OF THE PRONUCLEI BREAKDOWN -chromosomes condense and arrange themselves for mitotic cell division .