Fertilizin is a chemical substance produced from
Mature eggs
Acrosome
Polar bodies
Middle piece of sperm
Survival time of sperms introduced into the vagina may be
The eggs of elephant are
Which of these is used to control human population?
Neural crest cells break off from the ________ and later move to the sides of the developing embryo to form ________
In the first phase of gastrulation of amphibians there occurs the separation of