Unicellular organisms are believed to have formed from nonliving elements approximately years ago.

Unicellular organisms are organisms which contain single cells , they include bacteria, archaea, protozoa, unicellular fungi, unicellular algae among other organisms. Multi cellular organisms are those organisms made of made up of many cells these includes plants and large organisms. Unicellular organisms are believed to have formed from non-living elements approximately 3.5 billion years ago.