Question

“Bark cells are impervious to gases and water”. What experiment will you perform to prove this?

Answer 1

Hint: Bark is an outer covering of a tree which mainly helps in water conservation and also plays an important role in protecting the tree from the attack of diseases, pests etc. This layer is said to be impervious which means it does not get affected by the presence of water or air.

Complete answer:
In order to prove this, you need to perform an experiment where you collect the bark from different trees and place it in a container with a different environment. Let us take two cinnamon sticks which are nothing but the bark of a tree and are easily available in every kitchen. These sticks are placed in two different containers where one container is filled with water and the other container should be left empty so that only air is present. Leave the setup aside for a few hours and after sometime you will observe that there is no change in either of the containers. The bark placed in the container neither shrinks nor swells. This can be attributed to its impervious layer. As the bark cells do not show any change, it is said to be impervious to gases and water.
Hence, this is proved.

Note:
The bark cells are said to be impervious because there is a deposition of suberin in it. Suberin is a wax-like material that is hydrophobic which means water repelling and does not allow water molecules to penetrate into it. In some of the woody plants, bark contains few openings called lenticels.