You have a microorganism, and you have identified the components below. Which of these components tells you that you have a an archaeon, rather than a bacterium?

a. 705 ribosomes

b. Single circular chromosome

c. Plasmids

d. Presence of N-acetyltalosaminuronic acid in the cell wall

The correct answer is d. Presence of N-acetyltalosaminuronic acid in the cell wall.

Explanation:

Bacterial cell wall is made up of peptidoglycan which contains NAG and NAM units joined together by β (1-4) glycosidic linkage but the cell wall of archaea are different from the bacteria and called pseudo-peptidoglycan.

The cell wall of archaea is also called pseudomurein which is also composed of two units, N-acetylglucosamine and N-acetyltalosaminuronic acid and these two components are joined together by β (1-3) glycosidic linkage which is different from linkage in bacteria.

Therefore the correct answer is d. Presence of N-acetyltalosaminuronic acid in the cell wall.