Chapter 20, Problem 5AL

Summary Introduction

Archaea are referred to as prokaryotic unicellular organisms. They are the third domain of life. Archaea can be categorized into six groups based on morphological and physiological differences. However, Bergey’s manual of systemic bacteriology, a taxonomic organization divides archaea into two phyla such as Crenarchaeota and Euryarchaeota. All methanogenic microorganisms that belong to Euryarchaeota are known as methanogens.