Down syndrome is caused by a(n)
A) dominant lethal gene.
B) chromosomal aberration.
C) extra Y chromosome.
D) deletion of genetic material in chromosome pair 21.
E) a homozygous recessive gene.

Question

Quizplus · Accepted Answer

Down syndrome is caused by a chromosomal aberration, specifically the presence of an extra copy of chromosome 21 (trisomy 21), rather than a single gene mutation or alteration.

Down Syndrome Is Caused by A(n)