Level of Organisation

Level of Organisation

Principles of Organisation

  • Always remember that the levels of organisation in biology start from the smallest unit, atoms and molecules, and can escalate up to an entire ecosystem.
  • Every higher level of organisation is built from the lower levels and usually exhibits new properties not seen in the separate components. This concept is referred to as emergence.

Cellular Level

  • The cell is the smallest unit of life and represents the base sub-level in any organism’s hierarchy.
  • Different types of cells have different functions, including skin cells, nerve cells, and red blood cells.
  • Certain organisms, like bacteria, are unicellular, meaning they consist of a single cell. Others, including humans, are multicellular and consist of many cells.

Tissue Level

  • A tissue is a group of similar cells that work together to carry out a specific function.
  • Examples of tissues include muscle tissue, which makes movement possible, and epithelial tissue, which forms a protective barrier in the body.

Organ Level

  • When different tissues combine, they form an organ that performs a unique function.
  • Examples of organs include the heart, which pumps blood around the body, and the lungs, which facilitate breathing.

Organ System Level

  • A group of organs that work together to perform a broad function is known as an organ system.
  • For instance, the digestive system, which includes the stomach, liver, and small and large intestines, works to convert food into nutrients and eliminate waste.

Organismal Level

  • An individual living entity, such as a plant, animal, or human being, is referred to as an organism.
  • An organism is fully functional and represents the highest level of biological organisation on its own.

Populations and Communities

  • A population is a group of the same species living in a specific area, whereas a community consists of all the different species living together in the same area.

Ecosystems and Biosphere

  • An ecosystem includes all the living organisms in a particular area, along with the physical components of the environment (like air, soil, and water) with which they interact.
  • The broadest level of organisation is the biosphere, which encompasses all ecosystems on Earth.