Question

Consider the following statements:
Assertion (A): In cellular organization, the cells are arranged as loose cell aggregates and do not form tissues and are functionally isolated
Reason (R): Absence of sensory cells and nerve cells

• A. Both (A) and (R) are true, (R) is the correct explanation of (A)
• B. Both (A) and (R) are true, (R) is not the correct explanation of (A)
• C. (A) is true, but (R) is false
• D. (A) is false, but (R) is true

Hint:

Cellular organization = Porifera; no true tissues, only specialized cells. Absence of nerve/sensory cells is characteristic, hence Reason explains Assertion perfectly.

Answer 1

The Correct Option is A

In sponges (Porifera), cells are loosely arranged as aggregates (cellular level of organization). There is no true tissue differentiation, and cells act independently but are functionally specialized. Sensory cells and nerve cells are absent; the cells coordinate via chemical signals. Hence, both A and R are true, and R explains A.