In this live Grade 12 Life Sciences show we take a look at Meiosis. In this lesson we describe the events of each phase of Meiosis I and II. We state the importance of meiosis. We state what is meant by non-disjunction as well as the consequences of non-disjunction. We describe how non-disjunction of chromosome pair 21 in humans may lead to the formation of an abnormal gamete with an extra copy of chromosome 21. Finally, we describe how the fusion between the abnormal gamete and a normal gamete may lead to Down Syndrome.