Which of the following statements is false?

Options

A. Erythrocytes / RBC are the least abundant of all the cells in blood
B. The number of RBCs in adult man per `mm^(3)` of blood is 5 million to 5.5. million
C. RBC are formed in the red bone marrow in the adults
D. RBCs are enucleate in most of the mammals

Answer

To determine which statement is false, we need to analyze each of the provided statements regarding blood cells.

### Step-by-Step Solution:

1. **Evaluate the First Statement:**
- The first statement claims that erythrocytes (RBCs) are the least abundant cells in blood.
- This statement is incorrect. Erythrocytes are actually the most abundant cells in the blood, with approximately 5.5 million RBCs per cubic millimeter (mm³) of blood.

2. **Evaluate the Second Statement:**
- The second statement mentions that platelets are the most abundant.
- This statement is also incorrect. While platelets are numerous, they are not more abundant than RBCs. The normal range for platelets is about 150,000 to 350,000 per mm³, which is significantly less than the number of RBCs.

3. **Evaluate the Third Statement:**
- The third statement discusses leukocytes (WBCs) being the least abundant in blood.
- This statement is correct. The normal count for leukocytes is about 6,000 to 8,000 per mm³, making them the least abundant of the three types of cells mentioned.

4. **Evaluate the Fourth Statement:**
- The fourth statement states that RBCs are formed in the red bone marrow and that most of them are enucleated.
- This statement is also correct. Erythrocytes are produced in the red bone marrow and lose their nuclei during maturation.

### Conclusion:
Based on the evaluations:
- The first statement is false because it incorrectly states that erythrocytes are the least abundant cells in blood.

### Final Answer:
The false statement is: "Erythrocytes (RBCs) are the least abundant of all the cells in blood."