How do 'Archaebacteria' under kingdom Monera differ from normal bacteria?

Correct answer: Their cell wall structure is different, protecting them in harsh conditions

Direct answer: B. Archaebacteria, now commonly called archaea, differ from many typical bacteria in important cell-envelope features, including a distinctive cell-wall composition that lacks the usual bacterial peptidoglycan. Their membranes and other molecular features also help some groups tolerate extreme heat, high salt, or strongly acidic or oxygen-free habitats. A is not a defining difference because size can overlap between groups. C is false because archaea possess DNA as their genetic material. D is false because some archaea can move using specialised structures, while inability to move is not a universal characteristic. The safest exam link is: archaea have unusual cell walls and are often associated with extreme environments.