The loss of water is the form of vapour is called

Options

A. Wilting
B. Guttation
C. Transpiration
D. Ascent of sap

Answer

To answer the question, "The loss of water in the form of vapor is called," we need to analyze the options provided:

1. **Wilting**: This refers to the loss of rigidity in non-woody parts of a plant due to water loss. However, this loss is typically in the form of liquid droplets, not vapor.

2. **Gradation**: This term does not relate to the loss of water in any form and is not relevant to the context of plant biology.

3. **Transpiration**: This is the process by which water is absorbed by plant roots, moves through plants, and is released as vapor through small openings in leaves called stomata. This option directly relates to the loss of water in the form of vapor.

4. **Ascent of sap**: This refers to the upward movement of sap (which contains nutrients and water) from the roots to the leaves, but it does not specifically refer to the loss of water in vapor form.

Based on this analysis, the correct answer is **Transpiration**.

### Step-by-Step Solution:
1. **Identify the question**: The question asks for the term that describes the loss of water in vapor form.
2. **Review the options**: Look at each option provided (Wilting, Gradation, Transpiration, Ascent of sap).
3. **Analyze each option**:
- Wilting: Involves loss of rigidity due to water loss, but not specifically vapor.
- Gradation: Not relevant to water loss in plants.
- Transpiration: Correctly describes the loss of water in vapor form through stomata.
- Ascent of sap: Refers to upward movement of sap, not vapor loss.
4. **Select the correct answer**: Based on the analysis, the correct answer is **Transpiration**.