Abnormal meiosis Grade 12 Life Sciences Notes with Activities Questions and Answers

On this page you will find Abnormal meiosis Grade 12 Life Sciences Notes under Meiosis, which includes revision activities with questions and answers to help grade 12 learners to prepare for their tests and exams.


Sometimes mistakes occur during the process of meiosis.

  • This can happen in Anaphase 1 where the homologous chromosomes may not separate. Also called non-disjunction.
  • It can also happen in Anaphase 2 when there is non-disjunction of the sister chromatids.
  • If there is non-disjunction of chromosome pair 21 in humans it leads to the formation of an abnormal gamete with an extra copy of chromosome 21.
  • If there is fusion between a normal gamete and an abnormal gamete (with extra copy of chromosome 21) it leads to Down Syndrome.

If meiosis does not occur properly, an egg or sperm could end up with too many chromosomes, or not enough chromosomes.


Video Lesson on Abnormal meiosis

PDF Downloadable Notes on Abnormal meiosis:

Question and Answers Activities:

Find short and long questions for Grade 12 Life Sciences, which will help you to prepare for the exams, tests, practical tasks, and assignments.

More Resources

Meiosis Notes: What is meiosis, The process of meiosis in animal cells, The significance of meiosis, Abnormal meiosis, and Differences between meiosis I and meiosis II.

Abnormal meiosis Grade 12 Life Sciences Notes with Activities Questions and Answers

View all #Life-Sciences-Grade12 Study Resources

We have compiled great resources for Life Sciences Grade 12 students in one place. Find all Question Papers, Notes, Previous Tests, Annual Teaching Plans, and CAPS Documents.

Looking for something specific?