Life Process

Characteristics of Living Things

All the living things have some common characteristics which make them different from non-living things. The characteristics of living things are as follows :
(i) Living things can move by themselves.
(ii) Living things need food, air and water.
(iii) Living things can grow.
(iv) Living things can respond to changes around them. They are sensitive.
(v) Living things respire (release energy from food).
(vi) Living things excrete (get rid of waste materials from their body).
(vii) Living things can reproduce. They can have young ones.

All living things (organisms) also have an organized (cellular) structure with different levels of organization. An organized and ordered structure with cells, tissues, organs, organ systems, etc., is an important feature that distinguishes the living from the nonliving. If this organization breaks down, an organism is no longer alive as organization is not only confined to the external appearance, but is present in the internal structure as well. Therefore, living things have to repair and maintain their structures through various processes.

Life Process

The process that all living organisms perform to maintain their life is called life process. The basic life processes common to all living organisms are Nutrition and Respiration; Transport and Excretion; Control and Coordination (Response to stimuli); Growth; Movement and Reproduction.

Nutrition

It is a process by which an organism obtains nutrients from food and utilises them to obtain energy and for building repairing their tissues.

Nutrients

Nutrients are defined as the substances required for proper growth and maintenance of a living body, i.e. the materials, which provide energy to an organism. For example, carbohydrates, fats, proteins, vitamins and minerals.