Question: 153. Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus.
Reason (R): Presence of more than one nucleus in the tapetum increases the efficiency of nourishing the developing microspore mother cells.
In the light of the above statements, choose the most appropriate answer from the options given below:
(1) Both \mathbf{A} and \mathbf{R} are true and \mathbf{R} is the correct explanation of \mathbf{A}
(2) Both \mathbf{A} and \mathbf{R} are true but \mathbf{R} is not the correct explanation of \mathbf{A}
(3) \mathbf{A} is true but \mathbf{R} is false
(4) \mathbf{A} is false but \mathbf{R} is true
Answer: Option (3)
Explanation:
The tapetum is the innermost layer of the anther wall. Its cells are metabolically very active, possess dense cytoplasm, and commonly become multinucleate due to processes such as endopolyploidy or nuclear fusion.
Therefore, Assertion (A) is true.
The Reason (R) states that the presence of more than one nucleus increases the efficiency of nourishing developing microspore mother cells.
This statement is not correct. Tapetal multinucleation is a consequence of high metabolic activity but is not the direct cause of increased nourishment efficiency.
Its function is not explained solely by nuclear number.
Thus, Assertion (A) is true but Reason (R) is false, making Option (3) correct