Tag: reproductive system in frog

Vocal sacs are prominent in a male frog. It is composed of flexible skin which easily expands or contracts to change the frequency of sound waves and helps in amplification. The sound produced is a call for mating. The presence or development of the vocal sac is one way of externally determining the sex of a frog in many species. The vocal sac is open to the mouth cavity of the frog, with two slits on either side of the tongue. To call, the frog inflates its lungs and shuts its nose and mouth. So, the correct answer is option A.

In indirect development, an animal's birth form is different from the adult form. The embryo hatches from the egg in the larval form. The larva undergoes a drastic metamorphosis in order to achieve its adult stage. Frog, the adult form is completely different from the tadpole, its birth form. Hence, frog undergoes indirect development.
So, the correct answer is option B.

Males croak louder especially during the night in the breeding season. Males croak to the sound of vacuums, running water, loud noises, to attract females for mating and protect their territory from other male frogs. So, the correct answer is option D.

• Frogs are the amphibians and they are indulged in external fertilization. They are oviparous and they lay eggs. A male frog sheds millions of sperm and female sheds 2,000 to 3,000 eggs at a time in the water. 

When a sperm enters the cytoplasm of the oocyte, there is a cortical reaction, which prevents other sperms from fertilising that egg. The oocyte now (after sperm enters the oocyte) undergoes second meiotic division producing haploid ovum and releases a polar body.
So, the correct answer is option C.

In frog, from the outer smooth convex posterior side of each kidney arises a mesonephric or wolffian duct or ureter which passes backwards to open into the dorsal side of cloaca. In the males, the ureter dilates just posterior to the kidney to form a vesicula seminalis. Its function is to store sperms. 

In frogs, males frogs can be distinguished by the presence of to attract a mate, the male frog croaks from a shallow puddle, sending out ripples that invite not just female frogs, but also hungry bats. Male túngara frogs croak from shallow puddles to attract mates. Male frogs grow pads on their forelegs that help them to grasp the females in an embrace known as amplexus.

Female frogs listen to the croaking of male frogs, and this helps them choose the most suitable ones for mating. Another reason for which male frogs croak is to claim territory. By croaking loudly at night, a male frog warns other males that a particular part of a territory is already occupied.

In female frog, on each side of the ovary there is a long much coiled whitish glandular tube called oviduct or Mullerian duct. At the anterior end of each oviduct there is an oviducal funnel with a wide aperture called ostium.. The posterior part of the oviduct dilates to form a thin walled ciliated ovisac , where the ova are stored and agglutinated. So, the correct answer is 'Ova'.