1. AP Biology
The Cell Cycle
Part 2

2. Centrioles

4. Interphase

5. Before and after the S phase

6. Interphase cell (Look at the chromatin in the blue nucleus and the yellow cytoskeleton.)

7. Start of Mitosis

8. Cell in Prophase

9. Mitosis “Division of the nucleus”

10. Cell in Metaphase

11. Cell in Anaphase

12. Cell in Telophase and starting Cytokinesis

13. One cell becoming two

14. Motor Protein and the Spindle Fibers
Chromosome
movement
Kinetochore
Tubulin
subunits
Motor
protein
Microtubule
Chromosome

15. Animal vs. Plant

16. LE 12-10 Chromatin condensing Nucleus Chromosomes Cell plate 10 µm
Nucleolus
Prophase. The
chromatin is condensing.
The nucleolus is beginning to disappear.
Although not yet visible in the micrograph, the mitotic spindle is starting to form.
Prometaphase. We
now see discrete chromosomes; each
consists of two identical sister chromatids. Later
in prometaphase, the
nuclear envelope will fragment.
Metaphase. The spindle is complete, and the chromosomes, attached to microtubules at their kinetochores, are all at
the metaphase plate.
Anaphase. The
chromatids of each chromosome have separated, and the daughter chromosomes are moving to the ends of the cell as their kinetochore micro-
tubules shorten.
Telophase. Daughter nuclei are forming. Meanwhile, cytokinesis has started: The cell plate, which will divide the cytoplasm in two, is growing toward the perimeter of the parent cell.

17. Microscopic view of Mitosis in Onion root tips
Microscopic view of Mitosis in Onion root tips. Can you identify the stages?

18. Checkpoints (Is all going according to plan?)