Question

Assertion: The difference in shapes of leaves produced in air and those produced in water in buttercup represent the heterophyllous development due to the environment.
Reason: The phenomenon of heterophyllous is an example of plasticity.
A. Both assertion and reason are correct and Reason is the correct explanation for the assertion.
B. Both assertion and reason are correct but the reason is not the correct explanation for the assertion.
C. The assertion is correct but the reason is incorrect.
D. Both assertion and reason are correct.

Answer 1

Hint: There are various changes through which the plant goes so as to cope up with the alterations in the environment known as plasticity.

Complete answer: Different structures are developed during different phases of life as well as in reaction to the environment. To adapt to the changes the plant organ also changes its structures and is known as plasticity. Heterphyll is the occurrence of varied types of leaves on the same plant in different growth phases or under different environmental conditions.
In the case of environmental plasticity shown by aquatic buttercup ranunculus flagellates the leaves underwater are highly dissected while those above water are broad and lobed.
The leaves are the organs whose main function is photosynthesis.
Most leaves have a broad surface which enables them to absorb more light whereas most of them have thin surfaces giving them very little space for the diffusion of $CO_2$ inside and oxygen outside.
Leaves of submerged plants are thin, filamentous, or linear in shape.

So, the correct answer is “Option B”.

Note: Their vascular structure is not well developed and leaves usually lack stomata cells which means plants must directly absorb nutrients and exchange gas from water.