Question

Identify plants that show a modification of axillary buds into tendrils and hooks respectively.
a. Hugonia
b. Duranta
c. Passiflora
d. Dioscoea
A) a and b
B) c and a
C) b and c
D) d and a

Answer 1

Hint: The axillary bud is also known as the lateral buds. These are the embryonic buds which is present in the axil of a leaf. These buds are capable of forming shoots both vegetative and reproductive. It can be modified into tendrils for support or hooks for climbing.

Complete answer:
The tendrils are the thread-like structures which is the modification of the axillary bud and help the plant in climbing. It is the modification of the stem.
The hooks are the terminal leaflets which are curved so as to help the plant in climbing.
Let us discuss the plants given in the question:
a) Hugonia- These plants have branchlets that are leafless at the base. They have a curved hook-like modification that resembles a moustache. This hook or spine helps in climbing. It is the modification of the axillary bud.
b) Duranta- It is the genus of flowering plants which are mostly shrubs and small trees. There is no modification of axillary buds. The leaves and flowers of this genus are poisonous.
c) Passiflora- It is also known as passionflower. They bear tendrils and are mostly shrubs and trees. The tendrils are the modification of axillary buds. They have reduced leaves and suppressed axillary buds.
d) Dioscoea- This is the genus of many flowering plants. It is a tuberous herbaceous plant. The leaves are broad and heart-shaped.

Thus, the correct answer is option ‘B’.

Note: In case of pea, the stem is modified into tendrils. In the case of sweet pea, leaves are modified into tendrils. Some tendrils of the plants are sensitive to touch and another stimuli. They curl up on touching.