Question

Respiration without a distinct respiratory organ occurs in
A. Cockroach
B. Frog
C. Earthworm
D. Fish

Answer 1

Hint: Respiration is important for survival. Every organism needs to intake the gas it needs for survival and expel the unrequired. There are specific organs for doing this work. But some animals may do this with some other organ. Air is necessary for survival be it oxygen or carbon dioxide.

Complete answer:
Respiration is the intake and exhaling of air from the respiratory organ. Usually, all the creatures have a defined organ to do so but some primitive can do this jointly either by skin or some other organ.

> Option A - Cockroach: They respire by spiracles. They have their unique external valves which will transport the air directly into their trachea. They can hold their breath up to 7 hours.

> Option B - Frog: They have Lungs like us to respire. On the land, it will respire by lungs but in the water, they respire via their skin.

> Option C - Earthworm: They do not have any particular organ to respire. They respire through their moist body into the air and vice versa into the bloodstream. The oxygen diffuses in the body via the skin into the capillaries that lay just below the skin.

> Option D - Fish: We know fish have gills through which they respire. They are different from the lungs we have. Gills also give them buoyancy. They are present on both sides of their throat (pharynx).

Hence, the correct answer is option (C).

Note: Earthworm is invertebrate which is called a farmer’s friend. They have internal and external segmentation. They occur in soil. They have no legs, arms, eyes. They help in the decomposition of organic waste. They are usually used in fields to make the soil fertile.