1. Why is meiosis referred to as "Reduction Division"? What specifically is reduced when the cell divides during meiosis?
2. a) List three ways in which meiosis differs from mitosis. b) Which part of this process is most similar to mitosis, the first or second division (meiosis I or meiosis II)? Be sure to explain your answer - WHY do you think that division is most similar?
3. a) Following meiosis, how does the chromosome number of the daughter cells compare the chromosome number of the parent cell?
b) What does this tell you about the daughter cells' role in the body?
4. If either homologous pairs fail to separate in Meiosis I, or sister chromatids fail to separate in Meiosis II, the resulting gametes may have too many or too few chromosomes. These errors in meiosis are called NON-DISJUNCTION.
For the vast majority of chromosome pairs, the resulting daughter cell would be non-viable and that gamete would not be able to successfully fertilize. There are a few chromosome pairs where the gametes are able to complete fertilization and the resulting offspring is able to develop to term. Some examples of nondisjunction syndromes are Trisomy-21 (Down's Syndrome), Turner's Syndrome, and Kleinfelter's Syndrome.)
DO SOME RESEARCH! Find a non-disjunction disorder (you can use one of the ones mentioned or Google to find others). Explain how this disorder happens: which chromosome(s) are affected? At what stage in meiosis does the failure to separate occur? What are some of the symptoms associated with these conditions?