Question

Nondisjunction at meiosis II produces higher frequency of aneuploid gametes compared to meiosis I nondisjunction.

True or False?

Explain

Answer 1

False.

if non-disjunction occurs in the meiosis I the homologous chromosomes fail to separate and one daughter cell will get 2 copies of the chromosome and the other daughter cell will not have that chromosome. these cells undergo meiosis II, the first cell with 2 copies of the chromosome produces 2 daughter cells with 2 copies of that chromosome and the second cell with no copies of that chromosome produces 2 gametes without no copies of that chromosome.

If nondisjunction occurs in meiosis II the sister chromatids fail to separate, so one gamete from that cell will have 2 copies of that chromosome and the other cell will not have any copy of that chromosome. non-disjunction does not occur in the other cell so gametes arising from the other cell are all normal.

If non disjunction occurs in meiosis I all gametes are affected, if non-disjunction occurs in meiosis II only 2 cells are affected.