Haemophilia is

Options

A. A type of mosquito lacking haemocoel
B. The royal disease
C. Faulty blood clotting
D. Both (b) and (c)

Explanation

### Step-by-Step Solution:

1. **Definition of Hemophilia**:
- Hemophilia is a genetic disorder that affects the blood's ability to clot properly. This leads to excessive bleeding even from minor injuries.

2. **Nature of Hemophilia**:
- Hemophilia is classified as a sex-linked recessive disorder. This means that the gene responsible for hemophilia is located on the X chromosome, and males are more likely to be affected because they have only one X chromosome.

3. **Impact on Blood Clotting**:
- In individuals with hemophilia, the proteins that are essential for blood clotting are either absent or dysfunctional. This results in prolonged bleeding times, as the blood cannot clot effectively.

4. **Historical Context**:
- Hemophilia is often referred to as the "royal disease" because it was prevalent in the royal families of Europe, particularly due to Queen Victoria of the United Kingdom, who was a carrier of the disorder. Her descendants passed it on to various royal families across Europe.

5. **Conclusion**:
- Therefore, hemophilia can be described as a condition characterized by faulty blood clotting and is also known as the royal disease.

### Final Answer:
Hemophilia is a sex-linked recessive disorder characterized by faulty blood clotting, often referred to as the royal disease due to its historical association with Queen Victoria's lineage.

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