Studying the Purpose and Function of Mitosis in the Cell Cycle

1. Studying the Purpose and Function of Mitosis in the Cell Cycle By : Monica L. Ruiz-Baker Old Dominion University Menu Map

2. Background on the Cell Cycle and Mitosis C • The Cell Cycle has 4 stages. • Myth: The cell is inactive during Interphase. • Prior to Mitosis, the cell’s nuclear DNA replicates. • Mitosis is the division of nuclear DNA in somatic (non-sex) cells. • During Mitosis, the cell divides its chromosomes and separates into two identical daughter cells each containing identical nuclei. • Cytokenesis is the final Mitotic step whereby the nuclei, cell membranes, cytoplasm, and organelles divide into identical daughter cells. Mitosis T

3. Title Page The Cell Cycle Interphase Stages Menu Map Chromosomes Mitosis Prophase Metaphase Anaphase Telophase DNA Cell Content Protein Cell Content Questions Images Courtesy Of

4. The Cell Cycle I P M A T Chromosomes Mitosis DNA Content Protein Content

5. Interphase Stages C P • G1 : Active growth and Metabolism • S : DNA synthesis and metabolism • G2: Synthesis of molecules in preparation for cell division Mitosis Chromosomes

6. Chromosomes

7. Mitosis Chromosomes B C I P M A T DNA Protein

8. Prophase I Mitosis M • Early Prophase: Chromosomes condense and organize • Nuclear membrane and nucleoli disappear • Late Prophase: Centrioles form • Spindle apparatus assembled and attached to centromeres of duplicated chromosomes Chromosomes

9. Metaphase • Spindles use microtubules to line up the duplicated chromosomes along equator of cell Mitosis P A

10. Anaphase • Centromere of each duplicated chromosome is separated • Paired chromatids are pulled apart Mitosis M T

11. Telophase Mitosis B A • Chromosomes uncoil • Nucleoli reappear • Cytokenesis occurs • Plasma membrane of the cell pinches down along the equator creating two separate cells • Two genetically identical daughter cells are produced

12. DNA Content of Cells During the Cell Cycle C Mitosis

13. Protein Content of Cells During the Cell Cycle C Mitosis

14. Questions DNA Protein • How long did it take the above cell to complete a single cycle of the cell cycle? • In what phase were the cells in the first 8 hours? How do you know? • At approximately what time did division of the cytoplasm occur? • During what interval did G1 occur? How do you know? • What phases in the cell cycle occurred between the 8th and 12th hours of the experiment? • Explain the differences in the two graphs between the 14th and 20th hours of the experiment. 1 2 3 4 5 6

15. 20 hours Q Protein graph provides the answer!

16. Q S stage of Interphase DNA graph provides the answer!

17. Q 14 hours Both graphs provide the answer!

18. Q 14-20 hours DNA graph provides the answer!

19. Q G2 Look at both graphs!

20. Q Cytokenesis and G1 No change in DNA content of cells. Protein content increases as cells rebuild cellular organelles after cell division. Both graphs reveal the answers!

21. Images Courtesy Of: • Classroom Clip Art • Fotosearch • Developmental Biology Online • E-Bio Lab • Human Chromosomes • Chromatid Graph Data and Questions Courtesy of: E-Bio Lab