Question

Which of the following parts is responsible for the respiration in Earthworms?
A) Moist skin
B) Ctenidia
C) Clitellum
D) Typhlosole

Answer 1

The habitat of the earthworm is terrestrial. They are invertebrates and usually have an externally segmented body and have a tube-type of body. They are generally found in moist soil. They help in breaking down the organic matter that plants can use.

Complete answer:
-The scientific name of an earthworm is Lumbricina that belongs to the phylum Annelida of the order Opisthopora. The earthworms most commonly found in soils that are rich in organic matter.
-Earthworms are invertebrate therefore they lack a skeleton but usually maintain their structure with the help of a coelom chamber which is filled with fluid and acts as a hydrostatic skeleton.
-Specialised respiratory organs are not present in the earthworm. That's why they take Oxygen and give out carbon dioxide directly through their skin. -Diffusion of oxygen takes through the earthworm's body surfaces and there is the network of capillaries present just under the body surfaces through which oxygen diffuses inside their body.
-Usually, the air dissolves on the mucous of the earthworm's skin. Therefore they need to stay moist to breathe and they feel suffocation if the worms are dry out. Oxygen moves into the worm’s circulatory system as fresh air is taken in through their skin. Pumping of the oxygenated blood to the head area of the worm is taken place by the heart of the worm.
-Earthworms have Central and peripheral nervous systems.

Additional information:
Ctenidia - it is a respiratory organ or a gill in a mollusk like Octopus. It is a complex structure consisting of an axis with a row of projecting filaments.
Clitellum - near the head in the earthworm and leeches it is a non-segmented section of the body wall. It secretes a viscous fluid in which the eggs are stored and usually present between the 14th and 17th segments, near the anterior end of the body.
Typhlosole - in the earthworm, it is an internal food of the intestine that increases the surface area for the absorption of food.

So, the correct answer is, "moist skin".

Note:
-A thin layer of cuticle present on the skin of the earthworm that helps in keeping the skin of the earthworm moist and slimy.
-The exchange of gases that is taking Oxygen and giving out carbon dioxide takes place by the moist skin of earthworms.
-Earthworms will feel suffocation if their body becomes dry because of the inhibition of the exchange of gases.