The basic characteristics which are common among every living organism.
Biology is a science (natural), which involves the living organisms study and the study of their life. It includes the study of the chemical composition, physical structure, evolution, development and functioning of the organisms.
The biological science includes study of living organisms and the environment in which they survive. There are certain characteristics that are common to all the organisms, which are as follows:
(1) The organisms are organized: It possesses various levels of organization. An organism’s basic level is an atom. The atoms combine together and form the molecules, which makes up a complete cell. The cells, further form tissues and the tissues form organs. The organs combine together to form an organ system and then, a whole organism is developed.
(2) They acquire energy and materials: Energy is defined as the capacity for doing any work. Any energy or source of material is obtained from an external environment. Thus, humans acquire energy and materials for maintaining their organization and their metabolism.
(3) They are homeostatic: A cell’s ability for maintaining its internal environment is referred as homeostasis. Thus, in humans the organ systems are responsible for maintaining the homeostasis of an organism.
(4) They respond to stimulus: The living organisms respond to any external stimulus for maintaining the homeostasis. Responding to a stimulus includes motion.
(5) They grow and reproduce: An organism reproduces, when it passes its genetic information from one generation to another. Growth occurs in an organism, when there is increase in the size of an individual and also, in the number of cells.
(6) They have an evolutionary history: Evolution is defined as a process where a population keeps on altering over a period of time. It occurs by the mechanism of natural selection.