Question

Consider the following four statements (A - D) related to the common frog Rana tigrina, and select the correct option stating which ones are true (T) and which ones are false (F)?
Statements :
(A) On dry land it would die due to lack of $O_2$.
(B) It has four-chambered heart.
(C) On day land it turns uricotelic from ureotelic.
(D) Its life-history is carried out in pond water.

• A. (A)- T, (B)- F, (C)- F, (D)- T
• B. (A)- T, (B)- T, (C)- F, (D)- F
• C. (A)- F, (B)- F, (C)- T, (D)- T
• D. (A)- F, (B)- T, (C)- T, (D)- F

Answer 1

The correct option is A (A)- T, (B)- F, (C)- F, (D)- T

There are three chambers in a frog's heart - the left atrium, right atrium, and the ventricle.

There is only 1 ventricle in a frog's heart. In a frog, the blood mixes together in the ventricle.

Since frog larvae are aquatic they excrete ammonia. The terrestrial adult frog excretes urea.

The outer skin (epidermis) of frogs is moist. The moisture comes from mucus that's secreted by glands in the lower layer of skin (dermis).

Although frogs have lungs and take in air through their nostrils and mouth, they absorb additional oxygen through pores in their skin directly into their bloodstream.

This is a process called cutaneous gas exchange. Hence on dry land, it would die due to lack of O${}_2$. Usually frogs couple in the water through pseudocopulation.

Tadpoles move through water the same way fish do. After metamorphosis, frogs leave the water for more terrestrial life.

So, option A is correct.