Which statement is incorrect ?

Options

A. Mast cells and basophils secrete histamine and heparin
B. Mast cells are long lived, basophils are short lived
C. Mast cells are smaller than basophils with a bilobed nucleus
D. Mast cells are relatively sessile, basophils are mobile

Answer

To determine which statement is incorrect, we will analyze each of the provided options regarding mast cells and basophils.

### Step-by-Step Solution:

1. **Analyze the first statement:**
- **Statement:** "Mast cells and basophils secrete histamine and heparin."
- **Evaluation:** This statement is correct. Both mast cells and basophils are known to secrete histamine, which is involved in inflammatory responses, and heparin, which acts as an anticoagulant.

2. **Analyze the second statement:**
- **Statement:** "Mast cells are long-lived and basophils are short-lived."
- **Evaluation:** This statement is also correct. Mast cells can live for weeks to months, while basophils have a much shorter lifespan, typically only a few days.

3. **Analyze the third statement:**
- **Statement:** "Mast cells are smaller than basophils with a bilobed nucleus."
- **Evaluation:** This statement is incorrect. Mast cells are actually larger than basophils, with a size of around 10 micrometers. Additionally, mast cells have a round nucleus, not a bilobed one, which is characteristic of basophils.

4. **Analyze the fourth statement:**
- **Statement:** "Mast cells are relatively sessile and basophils are mobile."
- **Evaluation:** This statement is correct. Mast cells are typically found fixed in tissues (sessile), while basophils circulate in the bloodstream (mobile).

### Conclusion:
Based on the evaluations, the incorrect statement is the third one: "Mast cells are smaller than basophils with a bilobed nucleus."

### Final Answer:
The incorrect statement is: "Mast cells are smaller than basophils with a bilobed nucleus."

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