How do archaea differ from bacteria in terms of their cell membrane composition?

• A. Archaea have peptidoglycan in their cell walls, while bacteria do not.
• B. Archaea have a nucleus, while bacteria do not.
• C. Archaea are always multicellular, while bacteria are unicellular.
• D. Archaea have ether-linked lipids in their cell membranes, while bacteria have ester-linked lipids.

Answer: (D)

Verified step by step guidance

1. Understand the basic structure of cell membranes: Cell membranes are primarily composed of lipids, which form a bilayer that acts as a barrier to protect the cell.
2. Identify the types of lipids in archaea: Archaea have unique lipids in their cell membranes that are ether-linked. This means that the glycerol backbone is connected to the hydrocarbon chains via an ether bond (R-O-R').
3. Identify the types of lipids in bacteria: Bacteria have lipids in their cell membranes that are ester-linked. In this case, the glycerol backbone is connected to the hydrocarbon chains via an ester bond (R-COO-R').
4. Compare the stability and function: Ether bonds in archaea are more stable than ester bonds, which allows archaea to survive in extreme environments. This is a key difference in their adaptation and survival.
5. Summarize the key difference: The primary distinction in cell membrane composition between archaea and bacteria is the type of linkage in their lipids—ether-linked in archaea and ester-linked in bacteria.