Question

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

When the weight of the test tube $\left(A\right)\text{and}\left(B\right)$ is taken before and after the experiment, what is observed? Give reasons to justify your observation in $A\text{and}B$.

Answer 1

After the experiment, we observe test tube $A$ is raised up, i.e., a loss of weight is observed in test tube $A$.

In test tube $B$, the weight remains unchanged.

This is because test tube $A$ loses weight as the plant transpires and loses water.

In test tube $B$ there is no plant, so there is no transpiration.

Thus, the weight of test tube $B$ remains unchanged.