Answer and Explanation: Nondisjunction occurs when sister chromatids are not pulled apart at anaphase II. This will cause both sister chromatids/ homologous chromosomes to be pulled to just one pole of the cell.
Since the anaphase I stage in Meiosis I occurred without errors, this would result in four haploid gametes being produced.
However, two of these gametes will be normal, will have the normal number of chromosomes. The other two gametes would have an abnormal number of chromosomes and be aneuploid. One would have n+1 number of chromosomes, and the other would be n-1.