Prokaryota - GCSE Biology Definition

Prokaryota (also called prokaryotes) is a group of microscopic, single-celled organisms. They do not have a nucleus or other membrane-bound organelles, so their DNA floats freely in the cytoplasm. Prokaryotes include bacteria and archaea and are among the oldest and simplest forms of life on Earth. They can live in a wide range of environments, from the human gut to extreme conditions such as hot springs and salty lakes. Prokaryotes are important in processes like nitrogen fixation and decomposition, playing key roles in ecosystems and human health.