Title: Archaea | Microbiology
Headings: Archaea
Archaea
Learning Objectives
Crenarchaeota
Think about It
Euryarchaeota
Think about It
Finding a Link Between Archaea and Disease
Key Concepts and Summary
Multiple Choice
Fill in the Blank
Think about It

Content: Key Concepts and Summary
Archaea are unicellular, prokaryotic microorganisms that differ from bacteria in their genetics, biochemistry, and ecology. Some archaea are extremophiles, living in environments with extremely high or low temperatures, or extreme salinity. Only archaea are known to produce methane. Methane-producing archaea are called methanogens. Halophilic archaea prefer a concentration of salt close to saturation and perform photosynthesis using bacteriorhodopsin. Some archaea, based on fossil evidence, are among the oldest organisms on earth. Archaea do not live in great numbers in human microbiomes and are not known to cause disease. Multiple Choice
Archaea and Bacteria are most similar in terms of their ________. genetics
cell wall structure
ecology
unicellular structure
Show Answer
Answer d. Archaea and Bacteria are most similar in terms of their unicellular structure. Which of the following is true of archaea that produce methane?