Starch is mainly manufactured by

The epidermis in a dorsiventral leaf:
$(a)$ Covers both adaxial and abaxial surfaces
$(b)$ Is not covered by cuticle
$(c)$ Bears more stomata on the upper side
$(d)$ May even lack stomata on the upper side
Which of the above statements are correct?

In $Vallisneria$,stomata are

In an isobilateral leaf,more plastids are found in:

In a leaf,on which side is the phloem located?

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