Final answer:
Mitotic nondisjunction results in one trisomic and one monosomic daughter cell due to improper separation of sister chromatids during mitotic anaphase.
Step-by-step explanation:
Mitotic nondisjunction in a diploid cell produces a trisomic and a monosomic daughter cell. This event occurs when sister chromatids fail to separate properly during mitotic anaphase. As a result, one cell receives an extra chromosome (trisomic), while the other receives one less (monosomic).