The living organism exhibit distinctive characteristics, which are as follows:

1. Growth: All living organisms grow in size as well as in number. Plants show growth all through their life whereas animals up to a certain growth period after which growth ceases.

2. Reproduction: The process of reproduction is essential for the continuity of life on earth. Every organism whether unicelluar or multicellular gives rise to an individual of its own kind. Lower organisms usually reproduce asexually, e.g., Hydra, fungi, yeast, etc. Sexual reproduction is found in advanced group of organisms, which involves two parents. In Amoeba growth and reproduction however is synonymous.

3. Metabolism: There are thousands of enzymatically controlled reactions occurring in all living cells. These are synthesising (anabolic) and breaking down (catabolic) reactions. Hence, it is the most important characteristic of living organisms.

4. Response to stimuli Consciousness and response to stimulus is the defining property of all living organisms. Plants respond to light, water temperature. Unicellular organisms also sense their environment and respond accordingly.