Tag: frog - digestive system, circulatory system, excretory system and reproductive system

Frogs reproduce by external fertilisation. The female frog ovulates in the water and releases its gametes. The sperm released from the male frog fertilizes to form zygote which turns into a well-developed egg. So, the correct answer is option B.

Uricotelic animals excrete nitrogenous wastes as uric acid, which requires minimal water compared to urea or ammonia. This adaptation is especially useful for terrestrial animals that need to conserve water, such as birds, reptiles, and many insects.

When a frog is submerged in water, it stops pulmonary breathing and relies entirely on cutaneous respiration. Metabolic rate and oxygen consumption decrease, leading to bradycardia, which is a decrease in the heartbeat rate.

Animals can be distinguished in to cold blooded and warm blooded based on their body temperatures. Cold blooded animals can adjust their body temperature depending on their environment.

Frog exhibit sexual dimorphism. Male and female are distinguishable externally only during breeding season when the male develop roughed nuptial pads on the bases of the thumb. Nuptial pads help male in holding female, a sexual embrace called am plexus.

In frog, pancreas is made up of lobules, connective tissue and islets of langerhans. The islets of Langerhans secrete a hormone known as insulin. The pancreatic juice contains three enzymes. The trypsin, amylopsin and stoop sin or lipase.

Stomach of frog comprises a large broader anterior part called cardiac stomach and a short narrower posterior part called pyloric stomach. Fundic stomach is absent.

Stomach is followed by a coiled small intestine made of a small anterior duodenum and much longer posterior ileum. Jejunum is absent in frog.

Renal portal system of frog drains blood from hind limbs and posterior part of the trunk and supplies to the kidneys.

Ciliated columnar epithelium comprises columnar cells which have cilia on free surface. This epithelium lines most of the respiratory tract and fallopian tubes.