Which one of the following animals breathes through the skins?

Among the given options, the frog is the animal that breathes through its skin, a process known as cutaneous respiration [t1][t2]. While adult frogs possess lungs for breathing on land, they rely heavily on their moist, highly vascularized skin for gas exchange when submerged in water or during hibernation [c1][t9]. This adaptation allows oxygen to diffuse directly into the bloodstream from the environment [t3]. In contrast, fish primarily use gills to extract dissolved oxygen from water [c5], pigeons (birds) utilize a complex system of lungs and air sacs, and cockroaches (insects) breathe through a tracheal system consisting of small openings called spiracles. Amphibians like frogs are unique in utilizing three respiratory modes: cutaneous (skin), buccal (mouth lining), and pulmonary (lungs) depending on their life stage and habitat [t6][t10].

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 9: Life Processes in Animals > 9.2.2 Do other animals breathe the same way as humans do? > p. 133
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Activity 5.6 > p. 89
3. [3] https://en.wikipedia.org/wiki/Cutaneous_respiration