Read the following statement s and choose the correct option
In phenylketonuria the affected person does not secrete the enzyme to convert phenylalanine to tyrosine
(II)Possibility of male becoming haemophiliac is extremely rare
(III) Sickle cell anaemia is caused by the substitution of glutamic acid by valine at fifth position of beta chain of haemoglobin
(IV) Myotonic dystrophy is an autosomal dominant trait

Options

A. I and II alone are wrong
B. II and III alone are wrong
C. II alone is wrong
D. II and IV alone are wrong

Answer

To solve the question, we need to analyze each statement provided and determine whether they are true or false. Let's break it down step by step:

### Step 1: Analyze Statement I
**Statement I**: "In phenylketonuria, the affected person does not secrete the enzyme to convert phenylalanine to tyrosine."
- **Analysis**: Phenylketonuria (PKU) is indeed caused by a deficiency of the enzyme phenylalanine hydroxylase, which is necessary for converting phenylalanine to tyrosine. Therefore, this statement is **true**.

### Step 2: Analyze Statement II
**Statement II**: "Possibility of male becoming haemophiliac is extremely rare."
- **Analysis**: Hemophilia is an X-linked recessive disorder. Males have one X chromosome, so if they inherit the defective gene, they will express the condition. Females, on the other hand, need to inherit the defective gene on both X chromosomes to be affected, making female hemophiliacs rare. Thus, this statement is **false**.

### Step 3: Analyze Statement III
**Statement III**: "Sickle cell anaemia is caused by the substitution of glutamic acid by valine at the fifth position of beta chain of haemoglobin."
- **Analysis**: Sickle cell anemia is caused by a mutation where glutamic acid is substituted by valine, but this occurs at the **sixth** position of the beta chain of hemoglobin, not the fifth. Therefore, this statement is **false**.

### Step 4: Analyze Statement IV
**Statement IV**: "Myotonic dystrophy is an autosomal dominant trait."
- **Analysis**: Myotonic dystrophy is indeed an autosomal dominant disorder. Therefore, this statement is **true**.

### Conclusion
From the analysis:
- Statement I: True
- Statement II: False
- Statement III: False
- Statement IV: True

Thus, the correct option is that statements I and IV are true, while II and III are false.

### Final Answer
The correct option is that statements II and III are wrong, while I and IV are correct.

---