Haemophilia is a

Options

A. autosomal dominant disorder
B. outosomal recessive disorder
C. X-linked recessive disorder
D. X-linked dominant disorder

Answer

**Step-by-Step Solution:**

1. **Identify the Nature of Hemophilia:**
- Hemophilia is a genetic disorder. It is important to understand that genetic disorders are caused by abnormalities in genes or chromosomes.

2. **Understand the Alternative Name:**
- Hemophilia is also known as "Bleeder's disease." This name reflects the primary symptom of the disorder, which is excessive bleeding due to the inability of blood to clot properly.

3. **Mechanism of the Disorder:**
- In hemophilia, there is a deficiency in certain clotting factors in the blood. This means that when a person with hemophilia gets injured, their blood does not clot as it should, leading to excessive blood loss.

4. **Genetic Basis:**
- Hemophilia is linked to the X chromosome, making it a sex-linked disorder. This means that the genes responsible for hemophilia are located on the X chromosome.

5. **Recessive Nature of the Disorder:**
- Hemophilia is recessive in nature. For a person to be affected by hemophilia, they must have two copies of the mutated gene (in females) or one copy (in males).

6. **Genetic Expression in Males and Females:**
- In females (XX), both X chromosomes must carry the hemophilia gene for the female to be affected. If only one X chromosome carries the gene, the female will be a carrier but not affected.
- In males (XY), since they have only one X chromosome, having the hemophilia gene on that X chromosome will result in the male being affected.

7. **Conclusion:**
- Therefore, hemophilia is classified as an X-linked recessive disorder. The correct answer to the question is that hemophilia is a genetic disorder.