NEET-XII-Physics
Previous Year Paper year:2017
- #171Extrusion of second polar body from egg
nucleus occurs :
(1) after entry of sperm but before fertilization
(2) after fertilization
(3) before entry of sperm into ovum
(4) simultaneously with first cleavagedigAnsr: 1Ans : ( 1 )
Sol. Extrusion of second polar body from egg
nucleus occurs after entry of sperm but
before fertilization.
The entry of sperm into the ovum induces
completion of the meiotic division of the
secondary oocyte.
Entry of sperm causes breakdown of
metaphase promoting factor (MPF) and turns
on anaphase promoting complex (APC).