Which term describes bacteria that lack peptidoglycan in their cell walls?

• A. Archaebacteria
• B. Eubacteria
• C. Monerans
• D. Endospore

Answer: (A)

Cell wall composition is the clue here. Archaebacteria (archaea) have cell walls that do not contain peptidoglycan; they use different polymers, such as pseudopeptidoglycan or other materials, which sets them apart from true bacteria. Eubacteria are the organisms whose cell walls typically include peptidoglycan, so they don’t fit the description. Monerans is an old term that broadly referred to bacteria and similar unicellular organisms without clarifying wall chemistry, so it isn’t as precise. Endospore is not a group name; it’s a survival structure some bacteria form, not a descriptor of wall composition. So, the term for bacteria that lack peptidoglycan in their cell walls is Archaebacteria.