What are the characteristics of lifeSolutionAnswerChatac.pdf
- 1. What are the characteristics of life? Solution Answer: Chatacteristics of life: (1) Growth: All living organisms grow, but it is not the defining feature of organisms. It is because non living things, such as a sand dune can grow over time due to accumulation of more sand particles on it. Growth in living organisms are intrinsic (from inside) while those of non living things are extrinsic (from outside). More specifically, intrinsic growth is the defining feature of an organism. In unicellular organisms, growth and reproduction are synonymous. (2) Metabolism: All living organisms metabolise, that is they undergo varieties of biochemical reactions in the body, both to synthesize and degrade macromolecules. The sum total of the catabolic and anabolic processes in the body is called metabolism. It is the defining feature of living organisms. (3) Cellular organisation: All living organisms have cellular architecture, be it a multicelluar organism like humans or unicellular like a bacterium. The cell contains DNA which carries all the necessary informations to make the proteins required for carrying out biological functions. It is also a defining feature of living beings. (4) Reproduction: Living organisms are characterized by the ability to reproduce. But, it is not a defining feature of living organisms. For example, infertile couples, worker bees and mules cannot reproduce but are living. (5) Conciousness: This is another defining feature of living things. Conciousness is the ability of an organism to respond to changes in its environment, more specifically to external stimuli. Human beings are the only organisms to have self conciousness. (6) Energy: Living things take energy for their growth and functions. (7) Homeostasis: It is the process of maintaining a constant balance in the internal environment of the body and plays a crucial role in sustaining life.