The best known chromosomal abnormality associated with intellectual disability is __________; the most common type of this abnormality is __________.
A) Fragile X syndrome; trisomy 21
B) Tay-Sachs disease; trisomy 21
C) Down syndrome; trisomy 23
D) Tay-Sachs disease; trisomy 23
E) Down syndrome; trisomy 21

Question

Quizplus · Accepted Answer

Down syndrome is the best-known chromosomal abnormality associated with intellectual disability, and the most common type of this abnormality is trisomy 21, where an individual has three copies of chromosome 21 instead of the usual two.

The Best Known Chromosomal Abnormality Associated with Intellectual Disability Is