Which one of the following features is an indication for modification

Which one of the following features is an indication for modification of stem of a plant?

[amp_mcq option1=”Presence of ‘eye’ on potato” option2=”‘Scale’ found in onion” option3=”‘Tendril’ found in pea” option4=”‘Hair’ present in carrot” correct=”option1″]

This question was previously asked in
UPSC CDS-2 – 2018
The presence of ‘eye’ on potato is an indication for modification of stem of a plant.
Modifications are adaptations of plant parts for specific functions. To identify a modification, we look for features characteristic of the original plant part.
A) ‘Eye’ on potato: An ‘eye’ on a potato is an axillary bud, located at a node. The presence of nodes and internodes is a characteristic feature of stems. Potato tubers are modified underground stems used for storage and vegetative propagation.
B) ‘Scale’ found in onion: Onion bulbs consist of a reduced stem base and fleshy modified leaves (scales) that store food. While the bulb includes a stem component, the ‘scales’ themselves are modified leaves.
C) ‘Tendril’ found in pea: Tendrils in peas are modified leaves or leaflets used for support.
D) ‘Hair’ present in carrot: Carrots are modified taproots. Root hairs are extensions of epidermal cells of roots, not stems.
Thus, the presence of buds (eyes) on a potato directly indicates its stem nature, even though it’s modified into a tuber.
Other examples of stem modifications include rhizomes (ginger), corms (colocasia), bulbs (onion, garlic), runners/stolons (grasses, strawberry), thorns (Bougainvillea, citrus), and cladodes (Opuntia). Root modifications include taproots for storage (carrot, radish), adventitious roots for support (banyan), and pneumatophores for respiration (mangroves).
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