Withdrawal of which of the following hormones is the immediate cause of menstruation?
Progesterone
Estrogen
$FSH$
$FSH-RH$
Which part of ovary in mammals acts as an endocrine gland after ovulation
How many cleavages are completed in $16$ celled stage of egg.
Phallic organs in cockroach are related to
Which of these is used to control human population?
Spiral cleavage is found in