Which of the following genetic disorders are caused by the presence of an extra chromosome?
A)Down syndrome and Turner syndrome
B)Turner syndrome and sickle-cell anemia
C)Klinefelter syndrome and Down syndrome
D)phenylketonuria and XYY syndrome

Question

Quizplus · Accepted Answer

Klinefelter syndrome is caused by the presence of an extra X chromosome, while Down syndrome is caused by the presence of an extra copy of chromosome 21. Turner syndrome, sickle-cell anemia, phenylketonuria, and XYY syndrome are not caused by the presence of an extra chromosome.

Which of the Following Genetic Disorders Are Caused by the Presence