NEET BIOLOGY

Detailed explanation-1: -Neutrophils are the granular leukocytes that phagocytize pathogens (bacteria).

Detailed explanation-2: -The chemicals also attract white blood cells that “eat” microorganisms and dead or damaged cells. The process where these white blood cells surround, engulf, and destroy foreign substances is called phagocytosis, and the cells are collectively referred to as phagocytes.

Detailed explanation-3: -Polymorphonuclear neutrophils (PMNs) and monocyte/macrophages (MMs) are professional phagocytic cells that are able to phagocytose and destroy infectious agents. Therefore, they are key anti-infectious actors in host defense but can mediate tissue damages.

Detailed explanation-4: -Neutrophils engulf microbes only as they move over them, in a ‘vacuum-cleaner’ type of behaviour. This context-dependent nature of phagocytosis by neutrophils should be of particular relevance to human infectious diseases, especially for the early phase of encounter with microbes new to the host.

Detailed explanation-5: -Monocytes can phagocytose and present antigens, secrete chemokines, and proliferate in response to infection and injury. Once recruited to tissues, monocytes are capable of differentiating into macrophages and dendritic cells.