Question

Earthworm respires through
A) Moist skin
B) Ctenidia
C) Clitellum
D) Typhlosole

Answer 1

Hint:An earthworm is an invertebrate which lives in terrestrial habitat. They have an externally segmented body and show tube within a tube type of body. They are present in the moist soil.

Complete Answer:
Earthworm belongs to the order Opisthopora. It belongs to Annelida. They are commonly found in soil where the organic matter is sufficient. Being an invertebrate the earthworm lacks skeleton but maintains its structure by the help of fluid filled coelom chamber which acts as a hydrostatic skeleton. The body of earthworm is segmented and has setae on the segments.
The digestive system runs along the length of the body. Respiration is through skin and the circulatory system is made up of coelom. The circulatory system is simple and closed. They have central and peripheral nervous systems.
Ctenidia- It is the respiratory organ of mollusca like octopus.
Clitellum- It is a thick ring found on the unsegmented region of earthworm. It stores eggs.
Typhlosole It is present in the internal fold of intestine in earthworms. It increases the surface area for absorption of food.

Thus the correct answer is (A). Earthworms respire through moist skin.

Note:The skin of the earthworm has a thin layer of cuticle present on it. It helps in keeping the skin moist and slimy. This moist skin helps in exchange of gases i.e. intake of oxygen and expel carbon dioxide. The worm can die in the sun as the skin will become dry. This will inhibit the exchange of gases.