Question

When a chromosome pair fails to separate correctly in meiotic division, what is it called?

a. Chromosome deletions
b. Crossing-over
c. Nondisjunction
d. Trisomy

Answer 1

C. Nondisjunction.
Nondisjunction is the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division. This can result in deformities in a new-born such as Down Syndrome, due to lack of chromosomes in the body.