In which genetic condition, each cell in the affected person, has three sex chromosomes XXY?
Answer: (B) Kleinfelter's Syndrome. Answer: (B) Kleinfelter's Syndrome Solution: Klinefelter's syndrome is caused by the presence of an additional X-chromosome, giving each cell three sex chromosomes with a karyotype of 47, XXY.
- A.Thalassemia
- B.Kleinfelter's Syndrome✓
- C.Phenylketonuria
- D.Turner's Syndrome
Correct Answer
(B) Kleinfelter's Syndrome
Solution & Explanation
Answer: (B) Kleinfelter's Syndrome Solution: Klinefelter's syndrome is caused by the presence of an additional X-chromosome, giving each cell three sex chromosomes with a karyotype of 47, XXY. Turner's syndrome by contrast has a missing X (45, X0), so the condition with three sex chromosomes XXY is Klinefelter's syndrome. NCERT Reference: NCERT Class XII, Ch 4, p.76, lines 028-030: "Klinefelter’s Syndrome : This genetic disorder is also caused due to the presence of an additional copy of X- chromosome resulting into a karyotype of 47, XXY."