In the sequence of phagocytosis, which step comes after chemotaxis?

In the sequence of phagocytosis, which step comes after chemotaxis?

• A. Adherence
• B. Digestion
• C. Ingestion
• D. Chemotaxis

Answer: (C)

Phagocytosis proceeds in a defined sequence: chemical signals (chemotaxis) draw the phagocyte to the site of infection, then the phagocyte must attach to the target before it can be engulfed. This attachment, called adherence, is made possible by receptors on the phagocyte and is often enhanced by opsonins such as antibodies or complement that coat the microbe to make binding easier. Once adhesion has occurred, the phagocyte can proceed to ingestion, where it extends its membrane around the microbe to engulf it into a phagosome. Digestion then happens when the phagosome fuses with lysosomes to form a phagolysosome and enzymatic breakdown occurs. So the step immediately after chemotaxis is adherence, with ingestion following after adhesion.

Phagocytosis proceeds in a defined sequence: chemical signals (chemotaxis) draw the phagocyte to the site of infection, then the phagocyte must attach to the target before it can be engulfed. This attachment, called adherence, is made possible by receptors on the phagocyte and is often enhanced by opsonins such as antibodies or complement that coat the microbe to make binding easier. Once adhesion has occurred, the phagocyte can proceed to ingestion, where it extends its membrane around the microbe to engulf it into a phagosome. Digestion then happens when the phagosome fuses with lysosomes to form a phagolysosome and enzymatic breakdown occurs. So the step immediately after chemotaxis is adherence, with ingestion following after adhesion.