Question

A swollen leaf base is called ________
A. Pulvinus
B. Amplexicaul
C. Winged
D. Sheathing leaf base

Answer 1

Hint: A leaf is the part of the plant that is involved in the process of photosynthesis. Palisade mesophyll which is the primary photosynthetic tissue is known to be found on the upper side of the blade or lamina of the leaf. Leaves consist of distinct upper and lower surfaces that differ in the number of stomata and also amount of wax content.

Complete Answer:
- Leaves are of utmost importance of plants due to a variety of reasons- being broad and flat in size they permit light to penetrate the tissues and reach the chloroplast thereby promoting photosynthesis, they serve to store food and water, carry out the exchange of gases and pull water through the xylem due to transpiration.
- The leaves are made up of different tissues that include epidermis, mesophyll and vascular tissue. Leaf base is the region where the leaf is attached to the stem.
- A swollen leaf base is called pulvinus. Swelling of leaves is a phenomenon that is observed in members of the family Fabaceae. Swelling occurs as a result of change in turgor pressure and it is observed mostly during the night time. It in a way protects the axillary bud.

So the correct answer is A) Pulvinus.

Note: Leaves are very important structures that play a huge role in the survival of plants. They undergo many types of modification to combat a particular environment. One such example is swelling of the leaves. Another very common example is seen in Cactus plants where leaves are reduced to spines to minimize water loss.