(a) Name the four levels of organisation in living organisms. (ii) Explain two of the levels of organisation named in (a)(i) above

Answer Details

(a)(i) The four levels of organisation in living organisms

1. Cell
2. Tissue
3. Organ
4. System (organ system)

These build up in increasing complexity, from the cell as the smallest unit to systems which together form the whole organism.

(a)(ii) Explanation of two of the levels

Cell: The cell is the basic structural and functional unit of life. It is the smallest living part of an organism and can carry out all the processes of life such as respiration, feeding, excretion and reproduction. Examples include the amoeba (a single-celled organism) and individual cells such as red blood cells or muscle cells.

Tissue: A tissue is a group of similar cells that have the same origin and work together to perform a particular function. The cells are specialised for that function. Examples are muscle tissue (for contraction and movement), epithelial tissue (for covering and protection) in animals, and xylem or phloem tissue (for transport) in plants.