CELL BIOLOGY

PROPERTIES 

        The question, “what‘s life?” may appear quite native, because although a phenomenon called. “life” is quite obvious, at the same time it is also very complex.

      Living organisms is not merely a collection of basic atoms or molecules or elements viz. carbon, hydrogen, oxygen, nitrogen, sulphur, etc. but there are certain basic highlights or properties or characteristics which describe it.

Some of these are:

Cellular Organization: All organisms consist of one or more cells bounded by a membrane, which carry out basic activities of living organisms.

Ordered Complexity: All living things are complex but at the same time highly ordered. The cells are not  only organized but arranged in a hierarchical order which becomes more complex at each level e.g., the cells are grouped into tissues, which form organs, which in turn form organ systems and finally an organism.

Reproduction: “Life begets life”, i.e., living organisms produce their own kind and pass hereditart molecules to their offsprings. This is the most distinctive feature of living organisms.

Growth and Development: Most living organisms are multicelluar i.e., a single cell divides to form a number of cells, which increases both in size and number. Not only this they also undergo specialization e.g., they may form specialized cells viz. neurons, etc.

Regulation or Homeostasis:  All organisms maintain relatively “constant internal environment” by various mechanisms e.g. the water and salt concentration of body fluid, or blood glucose level or the degree of acidity or alkalinity are all kept at a stable or constant level.

Energy Processing: All organisms need energy, which they use for performing various kinds of work. This energy comes from the breakdown of various organic nutrients viz. carbohydrates, proteins, fats, etc. This energy is then used for carrying out various activities viz. locomotion or breathing.

Sensitivity or Response to the environment: All living organisms are sensitive to various stimuli viz. light, temperature, etc and then produce appropriate response to these stimuli of their environment e.g., plants grow towards light or we close our eyes in bright light or withdraw our hands from a hot object.

Evolutionary Adaptation: all living organisms interact with the other organisms as well as non-living environment. Both of these have a great effect on their survival. Therefore, in order to live successfully, they evolve adaptations to their environment e.g., animals living in cold environment have a thick coat of fur while those living in desert possess dry and scaly skin.