Down syndrome (trisomy-21)results from _________.
A) a mutagen
B) nondisjunction
C) a teratogen
D) a sex-linked mutation
E) an autosomal recessive allele

Question

Quizplus · Accepted Answer

Down syndrome is caused by nondisjunction during meiosis, where there is a failure to separate homologous chromosomes during either meiosis I or II, resulting in an extra copy of chromosome 21. This extra genetic material leads to the physical and intellectual characteristics associated with Down syndrome. A mutagen, teratogen, sex-linked mutation, or autosomal recessive allele do not result in the same genetic abnormalities seen in Down syndrome.

Down Syndrome (Trisomy-21)results from _________