The hormones of the sperm are called
Gynogamones$-I$
Androgamones
Gynogamones$-II$
None of these
The extra-embryonic membranes of the mammalian embryo are derived from
Vaginal orifice, urethral orifice are open in
What helps in the penetration of egg by the sperm
If an unfertilized egg is pricked with a micro needle, it will
Pasteels $(1945)$ described gastrulation takes place in aves by