Pic out the correct stataments
(I) Haemophilia is a sex-linked recessive disease
(II) Down's syndrome is due to aneuploidy
(III) Phenylketonuria is an autosomal dominant gene disorder
(IV) Phenylketonuria is an autosomal recessive gene disorder
(V) Sickle-cell anaemia is an X-linked recessive gene disorder

Options

A. I , III and V are correct
B. I and III are correct
C. II and V are correct
D. I, II and IV are correct

Answer

To solve the question, we need to evaluate each statement regarding genetic disorders and determine which ones are correct.

### Step-by-Step Solution:

1. **Evaluate Statement I: Haemophilia is a sex-linked recessive disease.**
- Haemophilia is indeed a genetic disorder caused by a mutation in genes responsible for blood clotting, and it is inherited in a sex-linked recessive manner. This means that the gene is located on the X chromosome, and the disorder manifests in individuals who inherit two copies of the recessive allele (in males, one copy is sufficient).
- **Conclusion:** This statement is **correct**.

2. **Evaluate Statement II: Down's syndrome is due to aneuploidy.**
- Down's syndrome (Trisomy 21) is caused by an extra copy of chromosome 21, which results from aneuploidy, a condition where there is an abnormal number of chromosomes in a cell.
- **Conclusion:** This statement is **correct**.

3. **Evaluate Statement III: Phenylketonuria is an autosomal dominant gene disorder.**
- Phenylketonuria (PKU) is actually an autosomal recessive disorder. It occurs when both parents pass on the recessive allele for the disorder, leading to the accumulation of phenylalanine in the body, which can cause serious health issues.
- **Conclusion:** This statement is **incorrect**.

4. **Evaluate Statement IV: Phenylketonuria is an autosomal recessive gene disorder.**
- As mentioned, PKU is indeed an autosomal recessive disorder, requiring two copies of the recessive allele for the condition to manifest.
- **Conclusion:** This statement is **correct**.

5. **Evaluate Statement V: Sickle-cell anaemia is an X-linked recessive gene disorder.**
- Sickle-cell anaemia is not X-linked; it is an autosomal recessive disorder. It is caused by a mutation in the hemoglobin gene on chromosome 11, not on a sex chromosome.
- **Conclusion:** This statement is **incorrect**.

### Summary of Correct Statements:
- The correct statements are:
- (I) Haemophilia is a sex-linked recessive disease. **(Correct)**
- (II) Down's syndrome is due to aneuploidy. **(Correct)**
- (IV) Phenylketonuria is an autosomal recessive gene disorder. **(Correct)**

### Final Answer:
The correct statements are I, II, and IV.

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