Which statement about Down syndrome is correct?

A) Down syndrome is caused by a third copy of chromosome 21.
B) Down syndrome is usually associated with chromosomal nondisjunction in meiosis.
C) Characteristics of Down syndrome include stubby fingers and a palm crease.
D) Individuals affected with Down syndrome display mental impairment.
E) All of the answer choices are correct about Down syndrome.

Down Syndrome

A genetic disorder caused by the presence of all or part of a third copy of chromosome 21, characterized by developmental delays and distinctive physical features.

Nondisjunction

An error in cell division that results in daughter cells with an incorrect number of chromosomes, leading to genetic disorders such as Down syndrome.

Chromosome 21

One of the 23 pairs of chromosomes in humans, with Down syndrome resulting from an extra copy of this chromosome.