AIIMS 2018 Botany Gymnosperms and Lycopsida MCQ Question

To answer this question, let's analyze both the assertion (A) and the reason (R) provided.

Assertion (A): "Sequoia is the longest tree among Gymnosperms."

Explanation of A: The assertion is indeed true. Sequoia, specifically the Giant Sequoia (Sequoiadendron giganteum), is known to be the tallest tree species in the world. It belongs to the group of Gymnosperms, which are seed-producing plants that do not form flowers or fruit. Gymnosperms include conifers, cycads, ginkgos, and gnetophytes. The tallest recorded Sequoia tree reaches heights of over 300 feet (about 91 meters).

Reason (R): "All members of Lycopsida are homosporous."

Explanation of R: This statement is false. Lycopsida, which includes the clubmosses and their allies, can be either homosporous (producing one type of spore) or heterosporous (producing two types of spores: microspores and megaspores). Therefore, it is incorrect to say that all members of this group are homosporous.

Evaluating the Options:

Now, let's evaluate the provided options based on our analysis:

A) Both A and R are true and R is the correct explanation of A.

• Incorrect: While A is true, R is false. Thus, this option cannot be correct.

B) Both A and R are true but R is not the correct explanation of A.

• Incorrect: A is true, but R is false, which makes this option invalid.

C) A is true but R is false.

• Correct: Since A is true and R is false, this option accurately reflects the relationship between the assertion and the reason.

D) A and R are false.

• Incorrect: This option is incorrect because A is true while R is false.

Conclusion:

The correct answer is C because the assertion about Sequoia being the longest tree among Gymnosperms is true, whereas the statement about all members of Lycopsida being homosporous is false.

This analysis helps clarify the relationship between the assertion and the reason, ensuring a clear understanding of both concepts in botany.