NEET2010ZoologyStructural Organisation in AnimalsActual
Assertion : Pharyngeal nephridia play a role in the conservation of water in the earthworm. Reason : They help the earthworm in keeping the skin moist for cutaneous respiration.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion
- BIf both assertion and reason are true but reason is not the correct explanation of assertion
- CIf assertion is true but reason is false
- DIf both assertion and reason are false.
Correct answer
C. If assertion is true but reason is false
Step-by-step solution
Pharyngeal nephridia occur in three pairs of bunches in the 4 th, 5 th and 6 th segments lying on each side of the alimentary canal. The ducts of the nephridia of the sixth segment open into the buccal cavity while the ducts from the nephridia bunches of the fourth and fifth segments open into the pharynx. These ducts carry excretory products from the pharyngeal nephridia into the gut. Enteronephric condition is an adaptation for the conservation of water which is absorbed by the inner lining of the alimentary cana