Question

Some leaves are modified to perform special functions. Explain.

Answer 1

Modification of leaves:

1. In certain plants, the leaves are modified to perform special functions.
2. These modifications include tendrils, spines, scale leaves and traps.

Leaf tendrils:

1. In plants with weak stems, the leaf is modified to develop into a thin coiled structure called tendrils.
2. Such plants can grow in the vertically upward direction coiling around a support using the tendrils.
3. Examples: pea plants and grapevines.

Spines:

1. In plants living in desert habitat, the leaves are modified to form spines.
2. Spines reduce the surface area of the leaf so that it can conserve water by reducing transpiration and protects the plant.
3. Examples: prickly pear and cactus.

Scale leaves:

1. In certain plants the leaves are modified to form scale leaves.
2. The scale leaves either protect the axillary bud or turn fleshy acting as the storage structure for food and water.
3. Examples: onion and ginger.

Insectivorous plants:

1. The leaves are modified to form traps in the insectivorous plant where after trapping the plant digests the insect.
2. Examples: pitcher plant, Venus flytrap and bladderwort.
3. In a pitcher plant, the leaf is modified to form a pitcher and a lid to trap insects entering the pitcher.
4. In Venus flytrap, the lamina of the leaf is modified to form the two sides of the trap and midrib acts as the hinge.
5. In bladderwort, the leaves are highly segmented and modified to form bladders which can close as the insects enter it.