________ is an inherited disorder caused by an extra 21st chromosome which results in mental retardation.
A)Phenylketonuria
B)Huntington's disease
C)Down syndrome
D)Turner's syndrome

Question

Quizplus · Accepted Answer

Down syndrome is caused by an extra copy of chromosome 21, leading to a total of 47 chromosomes instead of the normal 46. This results in characteristic physical features and developmental delays, including mental retardation. Phenylketonuria is a metabolic disorder, Huntington's disease is a genetic disorder that affects the nervous system, and Turner's syndrome is a chromosomal disorder affecting only females.

________ Is an Inherited Disorder Caused by an Extra 21st