In meiotic non-disjunction, meiotic products can be n+1, n-1, or n depending on when non-disjunction occurs. For the n+1 product can you tell if non-disjunction occurred in meiosis I or II if the non-disjunction happened to an autosome? What about a sex chromosome?
A) No; yes
B) No; no
C) Yes; yes
D) Yes; no

Question

Quizplus · Accepted Answer

It is not possible to determine if non-disjunction occurred in meiosis I or II based on the presence of n+1 products for an autosome. However, if the non-disjunction occurred in a sex chromosome, it can be determined because meiosis I and meiosis II produce different types of gametes. In meiosis I non-disjunction, the resulting gametes are n+1 and n-1 for sex chromosomes, whereas in meiosis II non-disjunction, the resulting gametes are n and n+2.

In Meiotic Non-Disjunction, Meiotic Products Can Be N+1, N-1, or N