Which of the following statements is incorrect ?

Options

A. Erythrocytes/RBCs 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. RBCs are formed in the red bone narrow in the adults
D. RBCs are enucleated in most of the mammals.

Explanation

To determine which of the statements regarding erythrocytes (RBCs) is incorrect, let's analyze each statement step by step.

### Step 1: Evaluate Statement 1
**Statement 1:** Erythrocyte (RBC) are the least abundant of all cells in blood.

- **Analysis:** This statement is incorrect. Erythrocytes (red blood cells) are actually the most abundant cells in the blood, not the least.

### Step 2: Evaluate Statement 2
**Statement 2:** The number of RBCs in an adult man per millimeter cube of blood is 5 million to 5.5 million.

- **Analysis:** This statement is also incorrect. The normal range for RBC count in an adult male is approximately 4.6 million to 6 million per millimeter cube of blood. Thus, while this statement is close, it does not accurately reflect the correct range.

### Step 3: Evaluate Statement 3
**Statement 3:** RBCs are found in the red bone marrow in the adult.

- **Analysis:** This statement is correct. Erythrocytes are produced in the red bone marrow in adults.

### Step 4: Evaluate Statement 4
**Statement 4:** RBCs are enucleated in most mammals.

- **Analysis:** This statement is also correct. In most mammals, mature red blood cells do not have a nucleus (they are enucleated).

### Conclusion
Based on the evaluations:
- Statement 1 is incorrect because RBCs are the most abundant cells in blood.
- Statement 2 is incorrect because the stated range is not accurate.
- Statements 3 and 4 are correct.

Thus, the incorrect statements are Statement 1 and Statement 2.

### Final Answer
The incorrect statements are:
1. Erythrocyte (RBC) are the least abundant of all cells in blood.
2. The number of RBCs in an adult man per millimeter cube of blood is 5 million to 5.5 million.

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