Annotation

 Living organisms, like any non-living matter, are composed of some basic elements. The same physical laws such as gravitation, magnetism, thermodynamics etc., also bind living organisms. Yet, living organisms differ from non-living in fundamental characteristics such as cellular organisation, nutrition, metabolism, growth and reproduction. It is these characteristics that make 'life'. Living organisms have a definite organisation consisting of structural and functional units called cells that make the physical basis of life namely protoplasm.Organisation refers to a kind of structure or system or situation where the smaller components become arranged into larger ones in a hierarchical order of complexity, to co-ordinate with one another in performing common functions or achieving common goals. Energy is the capacity to do work. All living organisms require energy for carrying on their vital metabolic activities. The primary source of energy for living system is solar radiation. The radiant energy of sunlight cannot be utilised directly by all living organisms. This ability rests only with the green plants. All the other organisms have to meet their energy requirement only through the green plants. Any state of a system where the rate of input of energy and matter is equal to the rate of dissipation of energy and output of materials, is called as a steady state.Living organisms do not survive indefinitely. Every organism dies after attaining a certain age or due to predation, disease, accident or other factors.Adaptations are favourable, heritable variations or changes that enable an organism to increase its chances of survival. Such variations are the result of genetic recombinations or mutations.  Death is the final termination of the life activities. Every living organism has a life cycle involving its birth, growth and death.Both living organisms and non-living matter are composed of some basic elements and are bound by the same physical laws. However, living organisms differ from non-living matter in some specific aspects.

Living systems