Archaea - GCSE Biology Definition

Archaea are a group of single-celled microorganisms that are distinct from bacteria and eukaryotes, forming one of the three domains of life. Despite their simple structure, archaea have unique biochemical and genetic characteristics, allowing them to live in extreme environments such as hot springs and salt lakes, as well as more moderate habitats. Unlike bacteria, their cell walls do not contain peptidoglycan, and their membranes have unique lipids. Archaea play important roles in nutrient cycles, including the carbon and nitrogen cycles, and are important for ecosystem functioning. Understanding archaea helps students appreciate the diversity and adaptability of life.