Question

In phagocytosis, foreign materials are engulfed and digested by immune cells. Before phagocytosis can take place there must be preliminary (nonspecific) attachment of the object to the phagocytic cell surface, followed by firmer specific attachment. The firm attachment and the ingestion of particles is facilitated by what serum substances?

Vesicles
Opsonins
Agretopes
Haptens
Immunotoxins

Answer 1

Opsonins, including complement factors and IgG antibodies, facilitate the firm attachment necessary for phagocytosis, allowing phagocytes to encapsulate and digest pathogens. Option B.

Step-by-step explanation:

In the process of phagocytosis, serum substances known as opsonins play a crucial role. Opsonins, such as complement factors, C-reactive protein, serum amyloid A, and antibodies like IgG, coat pathogens and facilitate their recognition by immune cells.

Phagocytes, including macrophages, dendritic cells, and neutrophils, have receptors that specifically recognize the Fc portion of IgG molecules or other opsonins, leading to a firm attachment and ultimately the engulfment and digestion of the foreign material.

Once bound firmly, the phagocyte extends part of its plasma membrane to envelop the pathogen. The pathogen becomes enclosed within a vesicle called a phagosome, which then fuses with a lysosome to form a phagolysosome. Hydrolytic enzymes within the lysosome digest the pathogen, completing the process of phagocytosis.

So Option b.