Question

Aestivation in which members of a whorl lie close but do not overlap is
A. Vexillary
B. Valvate
C. Imbricate
D. Twisted

Answer 1

Aestivation is the arrangement of sepals or petals of a flower within a flower bud before it has opened and there are many types of aestivation seen.

Complete answer:

If we look at options, option A is Vexillary. It is that type of aestivation where one large upper petal folds over and covers the smaller petals but in the question that aestivation is asked in which members of whorl lie close but do not overlap and this is not that type of aestivation. Therefore, this option is incorrect and it gets eliminated.
Moving to option B which is Valvate. It is that type of aestivation when sepals or petals in whorl and they touch one another at a margin but they do not overlap is called Valvate aestivation and in the question that aestivation is asked in which members of whorl lie close but do not overlap and this is that type of aestivation. Therefore, this option is correct.
Moving to option C which is Imbricate. In imbricate aestivation, out of 5 petals one is completely inside and one is completely outside and from the remaining petals one margin is overlapping and the other margin is overlapped. But in the question that aestivation is asked in which members of whorl lie close but do not overlap and this is not that type of aestivation. Therefore, this option is incorrect and it gets eliminated.
Last option D is Twisted aestivation. In this type of aestivation, one margin of appendages overlaps the next one but in the question that aestivation is asked in which members of whorl lie close but do not overlap and this is not that type of aestivation. Therefore, this option is incorrect and it gets eliminated.

Thus, the correct answer is option B i.e., Valvate aestivation.

Note:
In the question that aestivation is asked in which members of whorl lie close but do not overlap and this is valvate aestivation as sepals or petals in a whorl are close and they touch one another but none of the sepal or petal overlap. Therefore Valvate is the correct option.