Functions performed by modified axillary bud in Dioscorea, Bougainvillea and Cucurbita respectively are

Options

A. Vegetative propagation, protection, climbing
B. Photosynthesis, mechanical support, climbing
C. Sexual reproduction, climbing, vegetative propagation
D. Vegetative reproduction, photosynthesis, sexual reproduction

Answer

To answer the question regarding the functions performed by modified axillary buds in Dioscorea, Bougainvillea, and Cucurbita, we can break it down into three steps, one for each plant.

### Step 1: Dioscorea
- **Function**: In Dioscorea, the modified axillary buds are primarily involved in **vegetative propagation**. This means that if a part of the plant containing these buds is cut and planted, it can grow into a new plant. This is a common method of asexual reproduction in many plants.

### Step 2: Bougainvillea
- **Function**: In Bougainvillea, the modified axillary buds develop into **defensive structures** that resemble needle-like thorns. These thorns serve as a defense mechanism against herbivores and other threats, helping to protect the plant.

### Step 3: Cucurbita
- **Function**: In Cucurbita, which includes plants like pumpkins and gourds, the modified axillary buds transform into **tendrils**. These tendrils help the plant to climb and secure itself to supports, allowing it to grow upwards and spread out effectively.

### Summary of Functions:
- **Dioscorea**: Vegetative propagation
- **Bougainvillea**: Protection (defensive structures)
- **Cucurbita**: Climbing (tendrils)