Alternative mechanisms of non-disjunction that lead to trisomy
may occur either during Meiosis I (left) or Meiosis
II (right). Note that non-disjunction during Meiosis
I means that all products are trisomic or
nullisomic, whereas an event in Meiosis II does
produce standard products.
Figure ©2002 by Griffiths et al.; all text
©2014 by Steven M. Carr