#3) A person with trisomy 21 has an extra copy of chromosome 21. What happened during meiosis that caused the person to get three, instead of two, copies of chromosome 21?

A) nondisjunction
B) genetic recombination
C) Binary fission
D) Crossing Over

I'm thinking that sounds like C... but I'm not one hundred percent sure.

2 answers

Trisomy 21 (47,XX,+21) is caused by a meiotic nondisjunction event.
oh... okay, thanks