How do gram-positive and gram-negative bacteria structurally adapt to environmental pressures?

• A. Gram-positive bacteria have a thick peptidoglycan layer, while gram-negative bacteria have a thin peptidoglycan layer and a complex outer membrane.
• B. Both types have identical structural adaptations.
• C. Gram-negative bacteria have a thick peptidoglycan layer and lack an outer membrane.
• D. Gram-positive bacteria have a thin peptidoglycan layer and an outer membrane for protection.

Answer: (A)