In which of the following organism testes descends into scrotum in breeding season but in non-breeding season goes up

The extra-embryonic membranes of mammalian embryo are derived from

The foetal membrane which is the source of first blood corpuscle to enter the circulation of the embryo is called

The graafian follicle ruptures to release the secondary oocyte (ovum) from the ovary by the process called.....

In eggs which have very thick and resistant membrane e.g., fishes and insects sperm penetrate through a special canal called

The part of fallopian tube which is closer to the ovary is............