Which Eubacteria have a thick layer of peptidoglycans in their cell wall?

a) Gram positive bacteria.

b) Gram negative bacteria.

A. Gram positive bacteria

Explanation:

Gram-positive bacteria have the cell wall that consists of a single thick layer of peptidoglycan. This peptidoglycan layer is 20-80 nm thick in Gram-positive bacteria. On the other hand, the peptidoglycan layer in cell walls of Gram-negative bacteria is only 2-7 nm thick.

The thicker peptidoglycan layer of Gram-positive bacterial cells makes them more resistant to osmotic stress than the Gram-negative cells.