The first sign of a growing fetus can be noticed by:

How many of the following hormones are produced by the placenta?
Estrogen,Progesterone,Relaxin,$hCG$,$hPL$

Sometimes the separation of twins is incomplete and they are born attached and remain so even after birth. Such twins are known as:

$A$ : The morula passes through the phase of compaction,producing two major types of cells: the peripheral cells and the inner cell mass.
$R$ : The descendants of the inner cell mass become the trophoblast cells.

Which of the following hormones are secreted by the placenta?

Which part of the ovary acts as an endocrine gland after ovulation?