Question: 100 Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R :
Assertion A : The first stage of gametophyte in the life cycle of moss is protonema stage.
Reason R : Protonema develops directly from spores produced in capsule.
In the light of the above statements, choose the most appropriate answer from the options given below :
(1) \mathbf{A} is correct but \mathbf{R} is not correct.
(2) \mathbf{A} is not correct but \mathbf{R} is correct.
(3) Both \mathbf{A} and \mathbf{R} are correct and \mathbf{R} is the correct explanation of \mathbf{A}.
(4) Both \mathbf{A} and \mathbf{R} are correct but \mathbf{R} is NOT the correct explanation of \mathbf{A}.
Answer: Option (3)
Explanation:
In the life cycle of moss, the dominant plant body is the gametophyte.
The first stage of the gametophyte is the protonema stage, which is a green, filamentous structure.
This protonema develops directly from haploid spores that are formed inside the capsule of the sporophyte.
Later, the protonema gives rise to the leafy gametophore stage of moss.
Thus, Assertion A is correct.
Reason R correctly explains that protonema originates directly from spores,
which explains why it is the first stage of the gametophyte.
Therefore, both Assertion A and Reason R are correct,
and Reason R is the correct explanation of Assertion A.