Withdrawal of which of the following hormones is the immediate cause of menstruation?
Progesterone
Estrogen
$FSH$
$FSH-RH$
Trophoblast, is not involved in the formation of
Identify the correct option ($A$), ($B$), ($C$), ($D$) with respect to spermatogenesis.
Precocious puberty is
Embryonic body form stage is characterised by
The foetal membrane which is the source of first blood corpuscle to enter the circulation of the embryo is called