Cell

Cells are a fundamental component of all biological existence, often referred to as the 'building blocks' of life. Some organisms, such as bacteria, are unicellular; cells exist as independent units of life. Other higher organisms are multicellular, comprised of many cells. Within these multicellular organisms, groups of specialised cells collaborate to perform specific functions (these collaborations are referred to as tissues).

All cells adhere to specific fundamental principals, irrespective of their eukaryotic or prokaryotic classification. All cells must: have a plasma membrane, to separate the intracellular space from the extracellular space; contain heritable genetic material, to ensure the propagation of the species; contain intracellular compartments, to regionalise specific functions; regulate their osmotic gradient via the transportation of chemical species (ions, compounds, sugars) across their membrane.