Question

Assertion :Amphioxus has a simple organization compared to vertebrates. Reason: Many important craniate structures are lacking in Amphioxus.

• A. Both assertion and reason are correct and reason is the correct explanation for assertion.
• B. Both assertion and reason are correct but reason is not the correct explanation for assertion.
• C. Assertion is correct but reason is incorrect.
• D. Both assertion and reason are incorrect.

Answer 1

The correct option is A Both assertion and reason are correct and reason is the correct explanation for assertion.

Amphioxus is also called as lancelet. Amphioxus is devoid of heart, head, kidneys and paired limbs. Paired sense organs are absent here and receptors are of primitive types. A complete notochord is persistent with no vertebral column. These show that it has a simple organization compared to vertebrates because many important craniate structures are lacking in it. But it is definitely a simple chordate having a large number of primitive characters such as a notochord, dorsal hollow nerve cord, and gill clefts. Thus, the correct answer is option A.