Biosphere Contents

2. Diversity

Within an individual living organism there are a series of levels of organisation

  Nucleic acids store and express genetic information, while proteins have many functions within cells. Cells can divide and reproduce, and multicellular organisms are not usually just accumulations of similar cells, but rather are composed of many different kinds of cells, each specialised to carry out a particular function. Groups of similar cells form tissues which themselves are organised into organs, such as a kidney, or eye, which carry out particular functions. Organs with related functions form organ systems. Individual multicellular organisms such as humans contain within ourselves various organ systems, the functioning of which depends on effective central co-ordination of the whole. Individuals also exhibit behavioural responses to their external environment.

Fig fruit cell under electron microscope

Fig fruit under electron microscope

Fig being eaten by an ant

Fig trees

Forest from the air

How can the organisation of living things be represented?