Question

Select the correct flow of events in which monocyte act as part of nonspecific defense.

1. Monocyte cell membrane engulfs the pathogen and forms a membrane sac.

2. Lysosome combines with the membrane sac carrying the pathogen.

3. Monocyte reaches near the pathogen.

4. Monocyte expells the remnants of the pathogen.

5. The enzyme in the lysosomes destroys and digests the pathogen.

• A. 3$\to$ 2$\to$ 1$\to$ 5$\to$ 4
• B. 3$\to$ 1$\to$ 2$\to$ 5$\to$ 4
• C. 4$\to$ 5$\to$ 2$\to$ 3$\to$ 1
• D. 2$\to$ 1$\to$ 3$\to$ 5$\to$4

Answer 1

The correct option is B

3$\to$ 1$\to$ 2$\to$ 5$\to$ 4

Phagocytosis is the process in which certain cells like monocytes and neutrophils, engulf and destroy the germs/ pathogens. In this process, first, when the pathogen is encountered, the phagocyte moves towards it and engulfs it through the membrane. As a result, an internal membrane sac is formed. Next, the lysosome moves and combines with the membrane sac. Here, the enzymes of the lysosome digest the pathogen and is finally egested out of the cell.