Assertion : Bulliform cells are useful in the unrolling of leaf .
Reason : Bulliform leaves store water.

Options

A. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C. If the assertion is true but the reason is false
D. If both the assertion and reason are false

Answer

B

Explanation

In isobilateral leaves, the upper epidermis contains sepcialized cells, i.e., bulliform or motor cells. They are highly vacuolate and can store water, if available. However, in case of water deficiency the bulliform cells lose water and become flaccid. As a result the leaf gets rolled upto reduce the exposed surface. the bulliform cells are also useful in the unrolling of leaf during its development.