Introduction:
In gourd and cucurbita plants, a thread-like structure called a tendril arises from the stem. These tendrils play a crucial role in helping the plants climb and support their growth. Let's explore the details of how these tendrils function.

Structure of Tendrils:
Tendrils are slender, elongated structures that emerge from the stem of the gourd and cucurbita plants. They are usually green in color and exhibit a spiral or coiled shape. Tendrils possess a flexible and sensitive nature, allowing them to wrap around suitable supports for climbing.

Function of Tendrils:
Tendrils serve multiple purposes in the growth and survival of gourd and cucurbita plants. Their primary function is to provide support and help the plants climb. Here's how they accomplish this:

1. Sensing:
Tendrils have a remarkable ability to sense their surroundings. They can detect objects such as trellises, fences, or other plants nearby. This sensing mechanism is known as thigmotropism, which allows the tendrils to respond to touch or contact with an object.

2. Coiling:
Once a tendril senses a suitable support, it starts to coil around it. The coiling action is achieved through differential growth on opposite sides of the tendril. The side in contact with the support grows slower, while the opposite side grows faster, causing the tendril to wrap around the support tightly.

3. Anchoring:
As the tendril continues to coil, it creates a strong attachment to the support structure. This anchoring not only helps the plant climb but also provides stability and prevents it from being dislodged by wind or other external forces.

4. Growth:
The growth of tendrils is continuous, allowing the plant to reach higher levels of support. As the main stem grows, new tendrils are produced, ensuring the plant has a sufficient number of climbing structures.

Conclusion:
In gourd and cucurbita plants, tendrils are essential structures that enable climbing and provide support. Through their unique ability to sense, coil, anchor, and grow, these thread-like structures play a vital role in the growth and survival of these plants. By utilizing tendrils, gourd and cucurbita plants can reach greater heights, access sunlight, and maximize their chances of reproduction and survival.

The option is D CAN YOU EXPLAIN WHY?