The incorrect statement with regard to Haemophilia is

Options

A. It is recessive disease
B. It is a dominant disease
C. A single protein involved in the clotting in blood is affected
D. It is sex-linked disease

Answer

To determine the incorrect statement regarding hemophilia, we need to analyze the provided options based on our understanding of the disease. Here’s a step-by-step solution:

### Step 1: Understand Hemophilia
Hemophilia is a genetic disorder that affects the blood's ability to clot. This means that individuals with hemophilia may experience excessive bleeding due to their blood not clotting properly.

### Step 2: Analyze the Options
We have four statements to evaluate:
1. It is a recessive disease.
2. It is a dominant disease.
3. A single protein involved in the clotting in blood is affected.
4. It is a sex-linked disease.

### Step 3: Evaluate Each Statement
- **Statement 1**: "It is a recessive disease."
- This statement is true. Hemophilia is classified as a recessive disorder, specifically a sex-linked recessive disorder.

- **Statement 2**: "It is a dominant disease."
- This statement is incorrect. Hemophilia is not a dominant disease; it is a recessive condition.

- **Statement 3**: "A single protein involved in the clotting in blood is affected."
- This statement is true. Hemophilia is caused by the deficiency of specific clotting factors, such as Factor VIII or Factor IX.

- **Statement 4**: "It is a sex-linked disease."
- This statement is true. Hemophilia is located on the X chromosome, making it a sex-linked disorder.

### Step 4: Identify the Incorrect Statement
Based on the evaluations, the incorrect statement is:
- **"It is a dominant disease."**

### Conclusion
The incorrect statement with regard to hemophilia is that it is a dominant disease.

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