In the figure, which diagram of a bacterial cell wall contains teichoic acids?

• A. Diagram B: Thin peptidoglycan layer with outer membrane
• B. Diagram A: Thick peptidoglycan layer with teichoic acids
• C. Diagram C: No peptidoglycan, only a lipid bilayer

Answer: (B)

Verified step by step guidance

1. Understand the structural differences between Gram-positive and Gram-negative bacterial cell walls. Gram-positive bacteria have a thick peptidoglycan layer, while Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane.
2. Recall that teichoic acids are unique components found only in the cell walls of Gram-positive bacteria, where they are embedded within the thick peptidoglycan layer.
3. Identify that Diagram A, which shows a thick peptidoglycan layer, corresponds to a Gram-positive bacterial cell wall and is the one that contains teichoic acids.
4. Recognize that Diagram B, with a thin peptidoglycan layer and an outer membrane, represents a Gram-negative bacterial cell wall, which does not contain teichoic acids.
5. Note that Diagram C, showing no peptidoglycan and only a lipid bilayer, likely represents a different type of membrane structure (such as a mycoplasma) and does not contain teichoic acids.