Consider the following four statements (I-IV) related to the common frog Rana tigrina, and select the correct option stating which ones are true (T) and which ones are false ( F ) . I. On dry land it would die due to lack of O ₂ its mouth is forcibly kept closed for a few days. II. It has four-chambered heart. III. On day land it turns uricotelic from ureotelic. IV. Its life-history is carried out in pond water.

Step-by-step solution

Frogs respire on land and in the water by two different methods. In water, skin acts as aquatic respiratory organ (cutaneous respiration). Dissolved O ₂ in the water is exchanged through the skin by diffusion. On land, the buccal cavity, skin and lungs act as the respiratory organs. The respiration by lungs is called is called pulmonary respiration. In frog, heart has three-chambers, two atria and one ventricle, and is covered by a membrane called pericardium. The frog excretes urea and thus is a ureotelic animal.