Inhibition of uterine contraction ceases and the bleeding and cramps of menstruation begin due to
Increase in level of progesterone
Decrease in level of progesterone
Increase in level of $LH$
Decrease in level of $FSH$
During gastrulation the dorsal lip of blastopore (1 external sign of gastrulation) appears
The central nervous system develops as a result of
In vertebrates the nails are formed from
Sertoli cells are found in
Meroblastic cleavage refers to which type of division of egg