Which statement is true ?

Options

A. RBCs are devoid of nucleus in most of the mammals
B. In adult man 5 to 5.5 million RBCs/mm3 are present
C. Erythrocytes are the most abundant cells in blood and constitute almost 45 present of the blood
D. All statements are true

Answer

To determine which statement is true regarding red blood cells (RBCs), we can analyze each option provided:

1. **RBCs are devoid of nucleus in most mammals**: This statement is true. In most mammals, mature red blood cells do not have a nucleus. This adaptation allows them to carry more hemoglobin, which in turn increases their capacity to transport oxygen. The absence of a nucleus also contributes to their biconcave shape, which enhances their surface area for gas exchange.

2. **In adult man, 5 to 5.5 million RBCs per cubic mm are present**: This statement is also true. The normal range for RBC count in adult males is indeed between 5 to 5.5 million cells per cubic millimeter of blood. This is a standard reference value used in hematology.

3. **Erythrocytes are the most abundant cells in blood and constitute almost 45% of the blood**: This statement is true as well. Erythrocytes (RBCs) are the most numerous cells in the blood, making up about 40-45% of the total blood volume, depending on various factors including hydration and health status.

4. **All statements are true**: Since we have established that the first three statements are true, this statement is also correct.

**Conclusion**: All statements provided in the question are true.