Find out the total number of mendelian disorders from the following :
Cystic fibrosis , Haemophilia, sickle cell anaemia , colour blindness , Thalassemia, phenylketonuria

Options

A. 4
B. 5
C. 6
D. 3

Answer

To determine the total number of Mendelian disorders from the provided list, we will analyze each disorder based on its genetic inheritance pattern.

### Step-by-Step Solution:

1. **Identify Cystic Fibrosis**:
- Cystic fibrosis is an autosomal recessive disorder.
- **Conclusion**: Cystic fibrosis is a Mendelian disorder.

2. **Identify Haemophilia**:
- Haemophilia is a sex-linked recessive disorder.
- **Conclusion**: Haemophilia is a Mendelian disorder.

3. **Identify Sickle Cell Anaemia**:
- Sickle cell anaemia is an autosomal recessive disorder.
- **Conclusion**: Sickle cell anaemia is a Mendelian disorder.

4. **Identify Colour Blindness**:
- Colour blindness is a sex-linked recessive disorder.
- **Conclusion**: Colour blindness is a Mendelian disorder.

5. **Identify Thalassemia**:
- Thalassemia is also a sex-linked recessive disorder.
- **Conclusion**: Thalassemia is a Mendelian disorder.

6. **Identify Phenylketonuria**:
- Phenylketonuria (PKU) is an autosomal recessive disorder.
- **Conclusion**: Phenylketonuria is a Mendelian disorder.

### Summary of Findings:
- Cystic Fibrosis: Mendelian disorder (autosomal recessive)
- Haemophilia: Mendelian disorder (sex-linked recessive)
- Sickle Cell Anaemia: Mendelian disorder (autosomal recessive)
- Colour Blindness: Mendelian disorder (sex-linked recessive)
- Thalassemia: Mendelian disorder (sex-linked recessive)
- Phenylketonuria: Mendelian disorder (autosomal recessive)

### Total Count:
- Total Mendelian disorders identified: 6

### Final Answer:
The total number of Mendelian disorders from the provided list is **6**.

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