Select the chromosomal disorders from the following diseases affecting humans
I. Haemophilia
II. Down's syndrome
III. Klinefelter's syndrome
IV. Sickle cell anemia
V. Turner's syndrome
VI. Thalessemia

Options

A. All except II, III and IV
B. All except I and IV
C. All except I, IV and VI
D. All except I, III and VI

Answer

To solve the question of identifying chromosomal disorders from the given list, we will analyze each disease one by one.

### Step-by-Step Solution:

1. **Identify each disorder**:
- **Haemophilia**: This is a genetic disorder that affects the blood's ability to clot. It is caused by mutations in specific genes related to blood clotting factors. It is not a chromosomal disorder.
- **Down's syndrome**: This is a chromosomal disorder caused by the presence of an extra copy of chromosome 21 (Trisomy 21). Therefore, it is a chromosomal disorder.
- **Klinefelter's syndrome**: This is also a chromosomal disorder caused by the presence of an extra X chromosome in males (XXY). Thus, it is classified as a chromosomal disorder.
- **Sickle cell anemia**: This is a genetic blood disorder caused by a mutation in the hemoglobin gene. It is not a chromosomal disorder.
- **Turner's syndrome**: This is a chromosomal disorder that occurs when a female has only one X chromosome (45,X). Therefore, it is a chromosomal disorder.
- **Thalassemia**: This is a blood disorder caused by mutations in the genes that produce hemoglobin. It is not a chromosomal disorder.

2. **List the chromosomal disorders identified**:
- Down's syndrome (Trisomy 21)
- Klinefelter's syndrome (XXY)
- Turner's syndrome (45,X)

3. **Final selection**:
The chromosomal disorders from the list are:
- II. Down's syndrome
- III. Klinefelter's syndrome
- V. Turner's syndrome

### Conclusion:
The correct answer includes the following chromosomal disorders:
- Down's syndrome
- Klinefelter's syndrome
- Turner's syndrome