An organism is defined as any neighboring living system which is to be alive and performs various functions like growth, movement, reproduction, respiration, nutrition and excretion.
All organisms are made up of one or more cells. Cells aggregates to form tissue, tissue organize to form organs and organs system and finally body of the living organism. Cells are responsible for all metabolic activities in living organism.
Metabolism:
The sum of all biochemical activities occurring in the cell is called as metabolism. The material require for these metabolic activities are obtained form environment. There is a continuous flow of energy and matter between living organism and its environment. As a result of metabolic activities, grown and development is observed in a living organism.
Metabolic activities are divided into two types.
1) Anabolic process - It is a process of synthesizing complex molecules from simple one and is gaining energy.
2) Catabolic process - It is a process of breaking down complex molecule into simple one and is releasing energy.
Depending on the transfer of energy, living organisms are classified as below.
1) Autotrophic – Organism that converts light energy into chemical energy and then use it for its metabolic activity.
Plants are the examples of Autotrophic system and the process of converting light energy into chemical energy is called photosynthesis.
2) Heterotrophic – Organism that obtain their food from environment and surroundings and gets chemical energy from them and carry out all their metabolic activities.
Animals are the example of heterotrophic system.
Growth:
Growth is a result of metabolic activities. During the growth, the number of cells increases and as a result, the tissue increases and finally organs and the organism grow. Growth is higher when metabolic activities are more.
Growth results into morphogenesis and differentiation. Morphogenesis concerns with the shapes of tissues, organs and entire organism. It results into new forms. Differentiation is the process of transformation in cells to perform specific functions.
Reproduction:
All organisms have capacity to reproduce new organism and the process is called reproduction. Life perpetuates generation after generation through reproductions and results into increase in number of organism.
There are two types of reproduction – asexual and sexual reproduction. Bacteria are the example of asexual reproduction. Bacteria grows and reach to its maturity and splits into two organism. Bacteria don’t require two parents for reproduction and the new bacterium is identical to parent bacteria. All animals are the examples of sexual reproduction. Two parents are responsible for formation of new offspring.
Adaptation:
All organisms are affected by its surrounding environment and responds to light, temperature, sound etc. Organisms survive only when they adapt to their environment.
Death:
Death is an important characters of living organism through which the number of individuals of a species remains limited. The materials of dead organism go back to environment and help other organism for their survival.