Read Chapter 13.  Know all bold-face terms.  Figure 13.9 is an excellent overview of the differences between mitosis and meiosis.

1. What is a gene, a gene's locus and about how many genes might be on a single chromosome?
2. Briefly describe what is the same and what is different between a pair of homologous chromosomes.
3. Where in the human body does meiosis occur and what are the resulting cells called?
4. All sexual life cycles include an alternation of meiosis and fertilization.  Why must you have both processes?
5. What are the phases of  the first division of meiosis?  What are the phases of the second division of meiosis?  Which of these two divisions is similar to mitosis?
6. Prophase I of meiosis takes significantly longer than any other phase of meiosis.  What significant events occur during this time that do NOT occur during prophase of mitosis?
7. What is a tetrad? How many chromosomes are present in a tetrad?  How many chromatids?
8. Are the 2 daughter nuclei resulting from meiosis I haploid or diploid? Explain.
9. Do the 2 daughter nuclei resulting from meiosis I contain the same, less or more total DNA than the original parent cell (before chromosome replication)? Explain.
10. Compare the total amount of DNA in each of  the 4 daughter nuclei resulting from meiosis II to that of the original parent cell (before chromosome replication).
11. What are the 3 ways described in your text that sexual reproduction contributes to genetic variation?
12. Draw a diagram similar to Fig. 13.10 to illustrate the possible combinations of gametes following meiosis of a cell with a diploid number of 6 (2n=6).  How many combinations are possible, based on this drawing?
13. How many combinations of gametes are possible when a cell with a diploid number of 10 undergoes meiosis?
14. What is the synaptonemal complex, when does it form and what does it allow to happen?
15. Would crossing over between sister chromatids contribute to genetic variation?  Why or why not?
16. As we've just seen, sexual reproduction is a major source of genetic variation.  What is the other major source of genetic variation?