Which of the following statements in incorrect ?

Options

A. The RBCs of camel-are oval and enucleated.
B. Blood clotting factors are present in plasma
C. Human RBCs lack nuclei but have mitochondria
D. In adults erythropoiesis occurs in the bone marrow

Answer

To determine which statement is incorrect among the given options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Option 1: "The RBCs of camel are oval and enucleated."**
- This statement is **correct**. Camel RBCs are indeed oval in shape and do not have a nucleus (enucleated). Therefore, this option is not the incorrect one.

2. **Option 2: "Blood clotting factors are present in plasma."**
- This statement is also **correct**. Blood plasma contains various clotting factors, including fibrinogen, which is essential for the clotting process. Thus, this option is not incorrect.

3. **Option 3: "Human RBC lack nucleus but have mitochondria."**
- This statement is **incorrect**. Human RBCs do lack a nucleus, but they also lack mitochondria. Therefore, this option is indeed the incorrect statement.

4. **Option 4: "In adults, erythropoiesis occurs in bone marrow."**
- This statement is **correct**. In adults, the production of red blood cells (erythropoiesis) takes place in the bone marrow, which contains hematopoietic stem cells responsible for generating blood cells. Hence, this option is not incorrect.

5. **Final Evaluation:**
- After analyzing all the options, we conclude that **Option 3** is the incorrect statement.

### Conclusion:
The incorrect statement is: **"Human RBC lack nucleus but have mitochondria."**

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