Prokaryotes: Archaea

Prokaryotes split into archaea and bacteria early in life's history. Archaea, once thought to exist only in extreme environments, are now known to inhabit diverse habitats. They differ from bacteria in cell wall composition, plasma membranes, and RNA. Archaea are categorized into methanogens, halophiles, and thermophiles based on their living conditions.

What was the initial belief about the habitats of archaea?

• They lived only in cold environments.

• They were found in all types of environments.

• They lived only in extreme environments.

• They were found only in freshwater.

Which of the following is NOT a difference between archaea and bacteria?

• Ability to photosynthesize

• Type of plasma membrane peptides

• Presence of peptidoglycan in cell walls

• RNA and ribosomal protein structure

What is a characteristic of methanogens?

• They produce oxygen.

• They thrive in salty environments.

• They live in cold climates.

• They produce methane gas.

Where can halophiles typically be found?

• In extremely cold water

• In dry deserts

• In very salty conditions

• In oxygen-rich environments

Thermophiles are known to thrive in which type of environment?

• Cold ocean waters

• Deep sea vents and hot geothermal pools

• Dense forests

• High-altitude mountains