1. MITOSIS and the Cell Cycle
Chapter 9
MITOSIS and the Cell Cycle
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2. The Cell Cycle **Orderly set of steps between eukaryotic cell division
Why do Cells Divide?
Allow for growth
Reproduction and to make more cells
Repair/Replace dead or injured cells

3. Why are cells so small? Diffusion is inefficient over long distances.
Surface to volume ratio

5. Control of the Cell Cycle 
G1 Checkpoint - Check to see if DNA is damaged G2 Checkpoint - Check to see if DNA is replicated properly M Checkpoint - spindle assembly checkpoint, check for alignment of chromosomes 
Apoptosis - programmed cell death, if any of the checks fail

6. *sister chromatid: to either of the two identical copies (chromatids)
*Centromere holds together chromatids

8. How many chromosomes and why?
Chromosome video
Human chromosome
# is ________
# of pairs is______

9. 9.2 Mitosis & Cytokinesis
Interphase - cell growth, preparation for division, DNA synthesis. Cells spend most of their lives in interphase, it is the longest part of the cell cycle. (Some cells never leave interphase)

10. Mitosis Funnies:

11. Mitosis - The division of the nucleus that results in identical complete copies of chromosomes packaged into two new nuclei.
Occurs in 4 phases: Prophase, Metaphase, Anaphase, Telophase
Cytokinesis - The division of the cytoplasm that results in two daughter cells, occurs at the end of telophase.
**In plant cells, cytokinesis begins when a new cell wall forms between the two new cells. **In animal cells, the two new cells pinch and pull apart

12. Interphase • Prophase • Metaphase • Anaphase • Telophase
I-PMAT

15. STEPS OF MITOSIS: PROPHASE -Nuclear membrane disappears
-Spindle fibers appear
-Chromosomes become visible
spindle fiber: fine threads that extend from the poles
attaching to the chromosomes

16. METAPHASE -Chromosomes line up in the middle (the equator)

17. ANAPHASE
-Chromatids move AWAY to opposite poles
-Phase ends when chromatids reach the poles

18. TELOPHASE -The last “phase”
-Cell membrane pinches inward
-Daughter cells form
-Chromosomes disappear
-Asters and spindle fibers disappear

19. CYTOKENESIS
-Division of cytoplasm after Telophase

20. Interphase:  Resting
Prophase: Chromosomes visible, spindle forms as centrioles move
Metaphase:  Chromosomes line up along equator
Anaphase:  Chromatids separate
Telophase:  Nuclear membrane forms on each side, cytokinesis begins

21. Mitosis starts with a Parent cell and produces 2 daughter cells!!!!!!
The two daughter cells contain the exact same number of chromosomes as the original parent cell
Daughter cells are DIPLOID

22. **In plant cells, cytokinesis begins when a new cell wall forms between the two new cells. **In animal cells, the two new cells pinch and pull apart

23. 9.3 The Cell Cycle and Cancer
neoplasm: abnormal growth of cells
benign: non-cancerous
malignant: cancerous
Cancer: cellular growth disorder that results from the mutation of genes that regulate the cell cycle
Cancer cells
lack differentiation
have abnormal nuclei
form tumors
undergo metastasis & angiogenesis 

25. HeLa Cells Article on Henrietta Lacks
A HeLa cell (also Hela or hela cell) is a cell type in an immortal cell line used in scientific research. It is the oldest and most commonly used human cell line.
The line was derived from cervical cancer cells taken from Henrietta Lacks, a patient who eventually died of her cancer on October 4, 1951.

26. Name the phases starting at the top.

27. Name the phase
Identify X
Identify Y

28. 5. Name the phase

29. 6. Name the phase

30. 10. In humans, each cell (except sex cells) has how many chromosomes
11.  After mitosis, how many daughter cells are produced?  _______
12.  After mitosis (in a human cell), each daughter cell has how many chromosomes? _____
13.  How many phases are in MITOSIS? ___________
14.  Which phase of the cell cycle is the longest?  _________
15.  During which phase does cytokinesis begin?  __________