The figure given below represents an experimental setup with a weighing machine to demonstrate a particular process in plants. The experimental setup was placed in bright sunlight. Study the diagram and answer the following questions.

1. Name the process intended for study.

2. Define the above mentioned process. 

3. When the weight of the test tubes A and B is taken before and after the experiment, what change is observed? Justify.

4. What is the purpose of keeping the test tube B in the experimental setup? 

Answers:

1. Transpiration

2. The process of water loss from the leaves and other parts of the plants in the form of water vapor is called transpiration.

3. The weight of test tube A is taken before the test is higher compared to its weight after the test. Because the water from the test tube A is dead from transpiration.

The weight of test tube B is taken before and after testing remains the same because no water loss occurs in test tube B. This is because the oil enters the test tube.

4. The purpose of keeping the test tube B in the test setup makes the detection of changes in the test tube easier.