1 Molecules to Organisms: Structures and Processes

Organisms contain structures and processes organised from small to large. This organisation, though not much visible in small organisms, is quite noticeable in higher organisms. How are structures and processes organised in organisms? Every organism, whether small or big, contains cells as the smallest units. Cells, depending on their structures and biological roles, influence almost all structures, processes, and behaviour of the organism. In large organisms, cells combine to form structures and functions of tissues, which in turn form organs, organ systems, and organism in itself. It is, therefore, important to understand how interacting systems and subsystems coordinate to form behaviour, function, and emotion of the organisms.