Attributes of living organisms :
1. Growth : It is an intrinsic property of all living organisms through which they can increase cells both in number and mass.
(i) Addition of new protoplasm within the cells occur. Unicellular and multicellular organisms grow by cell division.
(ii) Plants show indefinite growth life throughout and animals show definite growth.
(iii) Growth in non-living objects is extrinsic. In bacteria growth occurs by cell division. Hence, growth and reproduction are mutually inclusive events.
2. Cellular Structure : Cells of living organisms may be prokaryotic or Eukaryotic.
3. Reproduction : It is a tendency of a living organism to perpetuate its own species.
(i) Asexual reproduction : Production of progeny with features more or less similar to parents. Eg : Conidia (Aspergillus penicillium), Budding (Hydra).
(ii) Sexual Reproduction : Variation is seen in progeny through recombination.
4. Response to stimuli :
(i) All living organisms are capable of sensing their environment and respond to various physical, chemical and biological stimuli.
(ii) Animals sense their surroundings by use of sense organs and is called Consciousness. In plants examples are bending of plants towards light. Closure of leaves in venus fly trap etc. This type of response is called Irritability.
5. Homeostasis:
(i) Property of self-regulation and tendency to maintain a steady state within an external environment which is liable to change is called Homeostasis.
(ii) Livig organism must maintain internal condition to survive in this environment.
(iii) Movement, Nutrition, Respiration and excretion are also considered as the property of living things.
6. Metabolism : The sum total of all the chemical reactions taking place in a cell of living organism is called metabolism.
