Question

Which of the following best defines nondisjunction?

A. Repetitive replications of the same piece of a chromosome
B. Complete exchange of chromosome pieces
C. Loss of a piece of a chromosome
D. Failure of chromosome pairs to separate

Answer 1

the answer is D. Failure of chromosome pairs to separate

Nondisjunction is a condition when sister chromosomes fail to separate proprly during cell division, leaving them with extra cromossom

Nondisjunction is the main cause of genetic abnormality which make an individual suffer from a down syndrome ( causing an intellectual impairment)