Life Processes for Class 10th

Life Processes for Class 10th

Life Processes for Class 10th

Life Processes for Class 10th: All those processes together do the work of maintenance of organisms calls life processes.

For example – Excretion, Respiration, Transport, Nutrition, etc.


Every living being takes food and from that food gets energy for the body, this process is called nutrition. Organisms require energy for all functions. Even when the organism is not doing any work, energy is needed to maintain bodily functions and this energy is obtained by nutrition.

Nutrition Methods

There are two methods of nutrition:

Autotrophic nutrition

Heterotrophic nutrition

Autotrophic nutrition: Those organisms make their own food in the presence of sunlight with the help of simple organic substances like carbon dioxide and water. They call it autotrophic.
Autotrophs contain a green pigment known as chlorophyll.

Heterotrophic nutrition: Organisms that depend on other organisms for their food such as humans, dogs, cats, etc. Some non-green plants, such as yeast, are heterotrophs in origin because they depend on plants or other organisms for their food.


Green plants form carbohydrates by using CO2 and water in the presence of chlorophyll in sunlight and give out oxygen gas. This process call photosynthesis.

Stages of Photosynthesis

  • (a) Absorption of light energy by chlorophyll.
  • (b) Conversion of light energy into chemical energy.
  • (c) The decomposition of water molecules into hydrogen and oxygen.
  • (d) Reduction of carbon dioxide into carbohydrates.

Green plants appear green due to the chlorophyll present in them. Leaf cells contain green dotted organelles, call chloroplasts, which contain chlorophyll. This chlorophyll present in green leaves absorbs energy from sunlight and converts it into chemical energy.

Trees take water from the ground through roots and get energy from sunlight through chlorophyll. The leaves have microscopic stomata holes on their surface, through these stomata holes the leaves absorb carbon dioxide from the air.

The exchange of gas in the leaves takes place through these stomata holes. The exchange of gases in trees plants, apart from these stomata holes, plants also exchange gases from the surface of the stem, root, and leaves.

A sufficient amount of water is also lost from these stomata holes of trees, so when carbon dioxide is not required for photosynthesis, these stomatal pores get close.

The opening and closing of pores are the functions of guard cells. When water enters, the guard cells swell and open the stomata, and when the guard cells contract, the pore is closed. When the hole is closed, there is no loss of water from the trees.