Levels of organization

Levels of Biological Organization

Levels of Biological Organization

After Odum (1963)

Protoplasm

The living material of the cell

Cell

``collection of living matter enclosed by a barrier that separates the cell from its surroundings; basic unit of all forms of life'' (Miller and Levine, 2006)

Organ

``group of tissues that work together to perform closely related functions'' (Miller and Levine, 2006)

Organism

``any biological individual capable of self-sustained independent living including the functions of maintenance of its internal environment (homeostasis) and reproduction'' (EIC, 2011)

Population

A collection of monospecific organisms inhabiting the same area simultaneously

Community

A group of interacting populations, also inhabiting the same area simultaneously

Ecosystem

An interacting biotic community and the abiotic elements they interact with

Landscape

``Area that is spatially heterogeneous in at least one feature of interest.'' (Turner et al., 2001)

Biosphere

The physical domain of life on the planet