Survival time of sperms introduced into the vagina may be
$1-2$ days
$3-4$ days
$5-10$ days
$1$ week
From which embryonic structure develops the vertebral column
As a result of cleavages, if blastomeres are symmetrically placed around the polar axis the type of cleavage is known as
Endometrium is lining of
Proctodaeum in rabbit is
Placenta has an outer layer which is selectively permeable and hormone secreting which is known as