Question

Which is the correct sequence of events during the phagocytosis of a bacterium by a leucocyte ?
I. Food vacuole forms
II. Plasma membrane receptors detect anti gen on the surface of the bacterium.
III. Lysosomes fuse with the food vacuole
IV. Engults bacterium

• A. II $\to$ I $\to$ IV $\to$ III
• B. I $\to$ II $\to$ III $\to$ IV
• C. II $\to$ IV $\to$ I $\to$ III
• D. I $\to$ II $\to$ IV $\to$ III

Answer 1

The correct option is A II $\to$ I $\to$ IV $\to$ III

During phagocytosis, the antigens present on the bacteria are first recognized by the plasmamembrane receptors of the leucocyte, then the plasmamembrane folds internally forming a convulsion into which the bacterium is engulfed into the cell forming a pseudo-vacuole called food vacuole. The lysosomes having lytic enzymes for the bacteria fuses with the food vacuole and destroys the bacteria, later the residues inside the vacuoles are ejected out of the cell through plasmamembrhe correct sequence oane.

So, the correct option is is, II, IV, I and III.