Question

An abnormal human male phenotype involving an extra X chromosome (XXY) is a case of

• A. Down's syndrome
• B. Intersex
• C. Edward syndrome
• D. Klinefelter's syndrome

Answer 1

The correct option is D Klinefelter's syndrome

Klinefelter's syndrome has 47, XXY chromosomes. It is a genetic disorder in which there is at least one extra X chromosome to a standard human male karyotype or an additional Y chromosome to a standard human female, for a total of 47 chromosomes rather than the found in genetically typical humans.