Question

Cutaneous respiration takes place through
a) Gills
b) Lungs
c) Skin
d) Cell membrane

Answer 1

Hint: Animals stay in land or water or both or on land and in water. The major factor that helps these animals to survive is the respiratory organ.

Complete answer :
Animals can survive in all habitats in water, land and both on land and water. Earlier animals lived in water. The transition from water to land is an important landmark in the evolution of animals. This evolution is due to different respiratory organs. Aquatic animals have gills for respiration as gills can extract dissolved oxygen and thus directly enter the bloodstream. Land animals have lungs to take in atmospheric oxygen.

Certain animals live on land as well as in water. These animals are known as Amphibians. These animals have an additional mode of respiration i.e. they can respire through the skin also. This helps them to respire easily in water also as gills are absent in them.This respiration through the skin is known as cutaneous respiration. Many fishes also respire through the skin before proper gill development.

The respiration through the skin takes place due to vascularisation i.e. many blood vessels are seen under and near the skin that directly absorb oxygen from water. Apart from amphibians, earthworms also respire through the skin.

Thus the correct option is C.

Notes: The word 'cutaneous' means related to or affecting the skin.
Frogs show winter sleep (hibernation) and summer sleep (aestivation). This cutaneous respiration helps them to respire during these periods also.