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 find the total number of Mendelian disorders from the given list, we will analyze each disorder based on its inheritance pattern.

### Step-by-Step Solution:

1. **Identify the Disorders**: The disorders listed are:
- Cystic fibrosis
- Hemophilia
- Sickle cell anemia
- Color blindness
- Thalassemia
- Phenylketonuria

2. **Classify Each Disorder**:
- **Cystic fibrosis**: This is an autosomal recessive disorder.
- **Hemophilia**: This is an X-linked recessive disorder.
- **Sickle cell anemia**: This is an autosomal recessive disorder.
- **Color blindness**: This is an X-linked recessive disorder.
- **Thalassemia**: This is an autosomal recessive disorder.
- **Phenylketonuria**: This is an autosomal recessive disorder.

3. **Count the Mendelian Disorders**:
- Cystic fibrosis (1)
- Hemophilia (2)
- Sickle cell anemia (3)
- Color blindness (4)
- Thalassemia (5)
- Phenylketonuria (6)

4. **Total Count**: All six disorders follow Mendelian inheritance patterns. Therefore, the total number of Mendelian disorders is **6**.

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

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