Question

In terms of descending order of percentage proportions of leucocytes in human blood, which one is correct?

• A. Neutrophils $\to$ lymphocytes $\to$ monocytes $\to$ acidophils $\to$ basophils
• B. Neutrophils $\to$ basophils $\to$ lymphocytes $\to$ acidophils $\to$ monocytes
• C. Neutrophils $\to$ monocytes $\to$ lymphocytes $\to$ acidophils $\to$ basophils
• D. Neutrophils $\to$ acidophils $\to$ basophils $\to$ lymphocytes $\to$ monocytes

Answer 1

The correct option is A Neutrophils $\to$ lymphocytes $\to$ monocytes $\to$ acidophils $\to$ basophils

Neutrophils are the most abundant white blood cell, constituting 60-70% of the circulating leukocytes.

Lymphocytes are much more common in the lymphatic system than in blood. Lymphocytes are distinguished by having a deeply staining nucleus that may be eccentric in location, and a relatively small amount of cytoplasm, constituting 30% of the leucocytes.

Monocytes, the largest type of WBCs. They are 5.3% of the total leucocytes.

Eosinophils / acidophils compose about 2-4% of the WBC total.

Basophils are chiefly responsible for allergic and antigen response by releasing the chemical histamine causing the dilation of blood vessels. Because they are the rarest of the white blood cells (less than 0.5% of the total count) and share physicochemical properties with other blood cells, they are difficult to study.

Hence the correct option is A.