Tag: introduction to reproduction

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'.

Nephron of frog is short, it lacks Henle's loop because water conservation is not important in amphibians who reside near water. Whereas for other animals the loop of henle present in the nephron helps in water conservation. So, the correct answer is 'Frog'.

Metamorphism is a hormonal effect influenced by hormones. The metamorphism in frogs is under the control of thyroxine which is produced by the thyroid gland. Frogs live in water bodies with rich iodine content to produce thyroxine.The deficiency in iodine would result in a retarded growth.