Assertion: Bulliform cells are useful in the unrolling of leaf.
Reason: Bulliform leaves store water.
(a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
(c) If Assertion is correct but Reason is incorrect.
(d) If both the Assertion and Reason are incorrect.
Answer is: (b)
Explanation:
In isobilateral leaves, the upper epidermis contains specialized 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 up to reduce the exposed surface. The bulliform cells are also useful in the unrolling of leaf during its development.