Questions & Answers

Which is/are the respiratory organ(s) present in the frog?
a. Only lungs
b. Lungs, skin, and gills
c. Lungs and skin
d. Only skin

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Hint: Respiration is the exchange of gases between an organism and its surroundings. Breathing can occur in various ways in adult frogs, whether individually or in tandem.

Complete answer:
> Option A is incorrect. A frog can breathe like a person by drawing air through his nostrils and down through his lungs. However, the process by which air is drawn into the lungs is somewhat different from that of humans. They don't have ribs or a diaphragm, which helps to widen the chest in humans, thus reducing the pressure in the lungs and allowing air to flow outwards.

> Option B is incorrect. Frogs breathe through their lungs and pass gases by skin and mouth covering. Frogs lack functioning lungs at the larval stage of their development but can take in oxygen via a series of gills.

> Option C is correct. Frogs breathe by two different methods on land and in water. In water, the skin serves as the breathing organ (cutaneous respiration). In water, dissolved oxygen is transferred through diffusion through the skin. The buccal cavity, skin, and lungs behave like the respiratory organs on the ground. Lung respiration is called pulmonary ventilation. Thus, the respiratory organ(s) present in the frog are the lungs and skin.

> Option D is incorrect. Although frogs have usable lungs, a great deal of a frog's breathing happens through the skin. The moist skin of a frog is thin, and marbled with near-surface blood vessels and capillaries. The skin's moisture dissolved oxygen from the air and water around the frog and transmits it to the blood.

Hence, The correct answer is option (B).

Note: Mature frogs lose their gills and can carry oxygen into their bodies through functional lungs that are relatively underdeveloped compared to human lungs. When they are active, frogs rely on their lungs to breathe and need more oxygen than only the skin respiration can supply.