Pasteels $(1945)$ described gastrulation takes place in aves by
The fifth cleavage of the fertilized egg of frog results in the formation of
Enzyme present in sperm acrosome to dissolve egg membrane is
$A$ : The secretions of male accessory glands constitute the seminal plasma which is rich in fructose, calcium and certain enzymes.
$R$ : Fructose serves as a source of energy for the sperms.
Vas deferens receives a duct from seminal vesicle and opens into urethra as _________.