From The School of Biomedical Sciences Wiki
Jump to: navigation, search

A unicellular organism is an organism consisting of only a single cell. Examples of unicellular organisms include Protozoa such as amoeba, cilia and paramecium [1]. They are thought to have been the first organisms to evolve, dating back to over 3.8 billion years ago, making them one of the oldest forms of life[2].

Unicellular organisms are often used as models to study various processes that occur in the eukaryotic cell. One such example is Saccharomyces cerivisiae, commonly used by biologists to study processes such as mitosis and meiosis[3]. Unicellular organisms also demonstrate key features including locomotion, feeding and reproduction, allowing us to study much larger and more complex systems by first looking at how things function at a cellular level[4].


  1. World of Microbiology and Immunology (2003) Protozoa http://www.encyclopedia.com/topic/Protozoa.aspx Last accessed 23 October 2015
  2. Unicellular Organisms(2017) [cited: 18/11/17]; Available from: https://biologywise.com/unicellular-organisms
  3. Alberts, Bruce. Molecular Biology Of The Cell, 5Th Edition. New York: Garland Science, 2008. Page 33
  4. Michael Anissimov: What is a Unicellular Organism (2017) [cited: 18/11/17]; Available from: http://www.wisegeek.org/what-is-a-unicellular-organism.htm
Personal tools