Grade 8 Science : Main Biological Processes in Plants - Part 3

Dear Children, we have learnt the processes of photosynthesis and transportation in plants from the previous articles. This article will help you to get a brief understanding on another important biological process in plants.

Let’s discuss about the process of Transpiration in plants.

This is the process in which plants release water in the form of water vapor or moisture by evaporation through its pores or the aerial parts. Here, the plants lose water mainly through the stomata in leaves.  Transpiration fastens the rate of transportation in plants. Transpiration pull is an essential force required to draw the water upwards from the roots to the upper parts of the plants where it helps to keep the ascent of water and nutrients continuous. When water evaporates from the plant, it will help to cool off the plant and maintain the water cycle. This process supports the existence of all living components in the environment to a greater extent.

 

The rate of transpiration rises due to strong wind, strong light and intense heat. When transpiration takes place amidst dry conditions, the plants can wither and dry. Thus, the plants found in arid regions with extremely dry conditions showcase several adaptations, so that they can retain the water required for their biological processes. 

 

Examples : Leaves with more flesh (Eg: Aloe Vera) and a thick epidermis found in aerial parts(Temple Trees), leaves with reduced size, leaves turned to spines (Eg: Cactus) or scale leaves,  rolled leaves, leaves falling off trees during the dry season(Eg: Rubber), sunk stomata, hair being present on epidermis (Eg: Sunflower) and etc.

 

When you keep a branch of a plant covered by a polythene bag for some time, you will observe some droplets in the bag. You may put a few crystals of anhydrous copper sulphate on to them and you will notice that it turns from white (original color) to blue. So this experiment will prove that water is being lost by plants by evaporation that eventually facilitates the process of transpiration. 

 

 

 

 

 

 

by Mekhala Egodawele

Photo source : Internet