Question

Which is correct about respiration in Earthworm_______________.
(a)$O_2$ from the atmosphere diffuses into the blood and combine with haemoglobin of blood plasma
(b)Blood does not have an important role in ${{O}_{2}}$ transport
(c)Respires anaerobically
(d)${{O}_{2}}$ diffused from the air combines with haemoglobin of RBCs.

Answer 1

Hint: In earthworm the oxygen from the atmosphere is passed through the blood by a passive process. This type of respiration is also seen in certain amphibians and sea snakes. It is the only mode respiration in lungless salamanders.

Complete answer:
Earthworms lack specialized breathing organs, so the respiratory exchange occurs through moist body surface into their bloodstream. They have a blood cell and haemoglobin which is dissolved in blood plasma. This type of respiration is known as cutaneous respiration.

Additional Information:
 -The earthworm comes in Phylum Annelida and Class Clitellata. The Clitellata members do not have parapodia and their heads are less developed.
-Earthworms are terrestrial invertebrates that inhabit the upper layer of the moist soil.
-The earthworm eats decayed leaves and organic matter mixed in the soil.
-Specialized glands calciferous is present in the stomach to neutralise the humic acid present in the humus.
-They have a closed type of blood vascular system, consisting of blood vessels, capillaries and heart.
-The earthworm is hermaphrodite or bisexual which means testes and ovaries are present in the same individual.

So, the correct answer is, “ ${{O}_{2}}$ from the atmosphere diffuses into the blood and combines with haemoglobin of blood plasma.”

Note: -Earthworm eats the soil where the organic content is digested and absorbed in the gut, while the residual soil is discharged by its anus.
-The earthworm is divided into many segments where the anterior end consists of the mouth and the prostomium which is a lobe that serves as a covering for the mouth and helps in cracking the soil into which earthworm can crawl.