Modification of Leaves MCQ - Practice Questions with Answers

Modification of Leaves

Leaves can be modified to perform functions other than photosynthesis. The modifications of leaves are enumerated below:

a) Leaf tendrils: Leaves are modified into slender wiry and coiled structures called tendrils. The entire leaf or a part of it may be modified into tendril as follows:

• Terminal leaflets modified into tendril, e.g., Pisum sativum (Pea), Lathyrus odoratus (Sweet pea), Narvella.
• Entire leaf modified into tendril, e.g., Lathyrus aphaca (Wild pea).
• Leaf tip modified into tendril, e.g., Gloriosa.
• Petiole modified into tendril, e.g., Clematis.
• Stipule modified into tendril, e.g., Smilax.
• Midrib modified into tendril, e.g., Nepenthes.

b) Leaf Spine: It is a pointed structure formed either due to modification of entire leaf or some part of it. It serves the function of protection. 

• In Opuntia leaves of axillary branches are modified into spines.
• In Berberis entire leaf is modified into three spines.
• In Parkinsonia, Acacia and Zizyphus stipules are modified into spines.
• In Citrus first leaf of axillary branch modified in to spine.

c) Fleshy leaves: These are seen in onion and garlic for the storage of food.

d) Phyllode: In Australian acacia, the leaves are short lives. The petioles of these plants expand, become green and synthesize food. Such petioles are called phyllode. 

e) Trap leaves: The trap leaves are also called insectivorous leaves or carnivorous leaves. Plants having trap leaves usually grow in nitrogen-deficient soils (boggy soils). They have poorly developed root system. For example, pitcher plant and venus-fly trap.