Ans.
Lysozymes are hydrolytic enzymes, synthesized and secreted by various organisms as a defense mechanism against bacterial infections. Invertebrates show type-i lysozymes (invertebrate lysozyme).
Lysozyme kills gram-positive bacteria by breaking bacterial cell walls as it prevents polymerization of components, required for cell wall synthesis. Invertebrates do not have immune cells, such as T cell, B cells, and natural killer cells.
Thus, the correct answer is 'option b). enzymes such as lysozyme break down the cell walls of harmful bacteria.'
