1. Lecture 16 - Mitosis II

2. Meiosis is a specialized type of cell division that produces haploid cells
Diploid cells - have 2 copies of each chromosome. The somatic cells in an organism are diploid and are produced by mitosis (1 cell --> 2 genetically identical copies).
Haploid cells - have one copy of each chromosome. Reproductive cells of the gem line (sperm and eggs) are haploid and are produced by meiosis (1 cell --> 4 genetically dissimilar cells).

3. Sexual reproduction involves both haploid and diploid cells

5. Homologous chromosomes pair before lining up on the spindle during meiosis

6. Maternal and paternal chromatids recombine in paired chromosomes to form chiasma
Sister chromatids are held together by cohesins

7. Chiasmata ensure proper segregation of chromosomes in meiosis

8. Kinetochores on each sister chromatid function independently in meiosis II (like in mitosis)

10. Meiosis increases genetic variability
During meiosis, maternal and paternal chromosomes parceled at random, therefore, many genetically different gametes may come from one individual
Exchange of genes during crossing over further enhances genetic variability between chromosomes

11. 2 sources of reassortment generate new combinations of chromosomes

12. Errors during chromosome segregation result in gametes with incorrect numbers of chromosomes