Archaebacteria MCQ - Practice Questions with Answers

• These are primitive bacteria that mostly live in harsh habitats.
• Their cell walls lack muramic acid and peptidoglycan instead it contains protein and non-cellulosic polysaccharides
• They are of three major types i.e. Methanogens, Halophiles and Thermoacidophiles.
• Examples of archaebacteria include Methanobacterium, Thermoproteus etc.

Methanogens

• These are archaebacteria found in marshy areas.
• These archaebacteria decompose carbon dioxide and formic acid into methane.
• Methanogens are commercially used to produce gobar gas.
• Methanogens are found in the rumen of ruminant animals also where they help in digestion of cellulose.
• E.g. Methanobacterium, Methanococcus etc.

Halophiles

• These archaebacteria are found in salty areas.
• They can live in high salt condition because of the presence of special lipids in their membranes, presence of mucilage covering, absence of sap vacuole and high internal salt content.
• Halophiles are chemoheterotroph
• E.g. Halobacterium, Halococcus.

Thermoacidophiles

• These archaebacteria can tolerate high temperatures and high acid conditions.
• Thermoacidophiles contain enzymes that can operate at high temperatures.
• They are found in hot sulphur springs and thermal vents.
• These are chemosynthetic i.e. they use sulphur to synthesize their food.
• E.g. Thermoplasma, Thermoproteus.