Leaves become modified into spines in
- onion
- silk cotton
- Opuntia
- pea
Answer
(3) Opuntia
Solution
As per NCERT, leaves are often modified to perform functions other than photosynthesis: they are converted into tendrils for climbing as in peas, or into spines for defence as in cacti.
Opuntia is a cactus, so its leaves are reduced to spines, while the green flattened stem (phylloclade) photosynthesises.
In onion the fleshy leaves store food, in pea the leaflets are modified into tendrils, and in silk cotton the leaves are not spiny (the prickles on its trunk are outgrowths).
Answer: (3)