Question

Read the following statements:
A. The cell wall of bacteria provides strong structural support to prevent them from bursting and collapsing.
B. Bacteria can be classified as gram-positive and gram-negative based on the difference in the cell wall.

• A. Only A is correct
• B. Only B is correct
• C. Both A and B are correct
• D. Both A and B are incorrect

Answer 1

Answer: (C)

Cell wall not only gives shape to the cell and protects the cell from mechanical damage and infection, but it also helps in cell-to-cell interaction and provides a barrier to undesirable macromolecules. In Bacteria and BGA it is composed of peptidoglycan and DAPA.
Bacteria can be classified as gram-positive and gram-negative based on the difference in the cell wall.
Bacteria that retain blue or purple color are called gram +ve bacteria, e.g. Bacillus subtilis. The cell wall is single-layered. The cell wall consists of two layers outer wall is of lipopolysaccharide, and inner is of peptidoglycan or murein. Murein or mucopeptide is 70-80% in the cell wall. Teichoic acids are present in the wall.
Bacteria that become colourless are called gram -ve bacteria. e.g. E. coli. The cell wall consists of two layers outer wall is of lipopolysaccharide and inner of peptidoglycan or murein. It is 10-20%
Gram -ve bacteria show more resistance to antibiotics.