This about cell wall of gram-positive bacteria is true

The correct option is "All of the above".

To understand why all the given statements are correct, let us analyze the structural characteristics of the cell wall of Gram-positive bacteria step-by-step:

1. Multilayered Peptidoglycan:
The cell wall of Gram-positive bacteria comprises many layers of peptidoglycan (murein). Unlike Gram-negative bacteria, which have only a single or a few layers of peptidoglycan, Gram-positive cell walls contain a thick, multi-layered peptidoglycan network that constitutes up to 90% of the cell wall's dry weight. Therefore, the statement "cell wall comprises of many layers" is true.

2. Thickness of the Cell Wall:
Due to the multi-layered peptidoglycan structure, the cell wall of Gram-positive bacteria is significantly thicker (typically 20 to 80 nanometers) than that of Gram-negative bacteria (typically 7 to 8 nanometers). Thus, the statement "the cell wall is thicker than the associated gram-negative bacteria" is true.

3. Presence of Teichoic Acids:
Gram-positive bacterial cell walls contain unique polyalcohol phosphate polymers called teichoic acids (which include wall teichoic acids and lipoteichoic acids). These molecules are covalently linked to either the peptidoglycan layers or the underlying cytoplasmic membrane. They play essential roles in cell wall maintenance, cell division, protection, and antigenicity. These acids are absent in the cell walls of Gram-negative bacteria. Consequently, the statement "Cell wall comprises of teichoic acids" is true.

Since all three individual statements are correct, the comprehensive choice "All of the above" is the correct answer.