The amniotic fluid is taken out with the help of surgical needle and separation of the embryo cells present in this fluid is done by

$A$ : The male urethra is longer than the female urethra.
$R$ : It carries both urine as well as semen.

The undifferentiated primordial germ cells are larger in size and their chromatin rich nuclei are distinct in

The type of blastula formed in birds is

In human all the three germ layers are originated from

Graafian follicle contains