paired chromosomes

Can Nondisjunction Occur During Mitosis? Nondisjunction, in which chromosomes fail to separate equally, can occur in meiosis I (first row), meiosis II (second row), and mitosis (third row). These unequal separations can produce daughter cells with unexpected chromosome numbers, called aneuploids. What is nondisjunction in mitosis? Nondisjunction is failure of paired chromosomes to move to