Question

Archaebacteria differ from eubacteria in:

• A. Mode of nutrition
• B. Cell shape
• C. Mode of reproduction
• D. Cell membrane structure

Answer 1

The Correct Option is D

To determine how archaebacteria differ from eubacteria, we need to look at characteristics that are unique to each group. Although archaebacteria and eubacteria share some similarities, they also have distinct differences. The most notable and relevant differences between these two groups include:

1. Cell Membrane Structure: This is the most significant difference. Archaebacteria have unique lipids in their cell membranes which consist of ether linkages, while eubacteria generally have ester linkages in their lipid bilayers. The lipid composition in archaebacteria contributes to their ability to survive in extreme environments.
2. Mode of Nutrition: Both archaebacteria and eubacteria can be autotrophic or heterotrophic, thus this is not a distinguishing feature.
3. Cell Shape: Both archaebacteria and eubacteria can exhibit various shapes, including cocci, bacilli, and spirilli, so cell shape is not a distinctive feature.
4. Mode of Reproduction: Both groups reproduce asexually through binary fission, so the mode of reproduction is similar for both.

The correct option answering how archaebacteria differ from eubacteria is Cell membrane structure given that the unique lipid composition of archaebacteria's cell membranes provides a basis for their classification as a distinct domain of life.