Question

The WBC count of a person's blood sample is 8000/cu.mm. How many eosinophils and lymphocytes would be in the same blood sample approximately ?

• A. 300 - 500/cu.mm and 500 - 700/cu.mm, respectively
• B. 300 - 500/cu.mm and 1200 - 1500/cu.mm, respectively
• C. 100 - 120/cu.mm and 160 - 200/cu.mm, respectively
• D. 160 - 240/cu.mm and 1600 - 2000/cu.mm, respectively

Hint:

Logic Tip: Use the mnemonic \textbf{N}ever \textbf{L}et \textbf{M}onkeys \textbf{E}at \textbf{B}ananas to remember the order of abundance: Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils.

Answer 1

The Correct Option is D

Concept:
White Blood Cells (WBCs), or leukocytes, are divided into different types based on their morphology and function. The Differential Leukocyte Count (DLC) provides the standard percentage of each type of WBC in a healthy human's blood. To find the absolute number of a specific cell type, apply its standard percentage to the total WBC count.
Step 1:
According to standard physiological data:
• Neutrophils: 60 - 65% (Most abundant)
• Lymphocytes: 20 - 25%
• Monocytes: 6 - 8%
• Eosinophils: 2 - 3%
• Basophils: 0.5 - 1% (Least abundant)
Step 2:
Total WBC count = 8000 $mm^3$. Eosinophils make up 2% to 3% of the total count. Minimum expected = $2% \text{ of } 8000 = \left(\frac{2}{100}\right) \times 8000 = 160$ Maximum expected = $3% \text{ of } 8000 = \left(\frac{3}{100}\right) \times 8000 = 240$ Therefore, the expected eosinophil count is 160 - 240 cu.mm.
Step 3:
Lymphocytes make up 20% to 25% of the total count. Minimum expected = $20% \text{ of } 8000 = \left(\frac{20}{100}\right) \times 8000 = 1600$ Maximum expected = $25% \text{ of } 8000 = \left(\frac{25}{100}\right) \times 8000 = 2000$ Therefore, the expected lymphocyte count is 1600 - 2000 cu.mm.
Step 4:
The calculated range for Eosinophils is 160 - 240, and for Lymphocytes is 1600 - 2000. This perfectly corresponds to Option (4).