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Chapter 9MITOSIS

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

9.1 The Cell Cycle

**Orderly set of steps between eukaryotic cell divisions

Why do Cells Divide?

Growth Reproduction (in single celled organisms) Repair

a. ________________

b. ________________

c. _________________

d. _________________

e. _________________

f. __________________

f.

Control of the Cell Cycle G1 Checkpoint - Check to see if DNA is damagedG2 Checkpoint - Check to see if DNA is replicated properlyM Checkpoint - spindle assembly checkpoint, check for alignment of chromosomes

Apoptosis - programmed cell death, if any of the checks fail

9.2 Mitosis & Cytokinesis

Mitosis - The division of the nucleus that results in identical complete copies of chromosmes packaged into two new nuclei

Cytokinesis - The division of the cytoplasm that results in two daughter cells

Interphase • Prophase • Metaphase • Anaphase • Telophase

IPMAT

Interphase: RestingProphase: Chromosomes visible, spindle forms as centrioles moveMetaphase: Chromosomes line up along equatorAnaphase: Chromatids separateTelophase: Nuclear membrane forms on each side, cytokinesis begins

**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

9.3 The Cell Cycle and Cancerneoplasm: 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

Mitosis produces 2 daughter cells

The two daughter cells contain the exact same number of chromosomes as the original parent cell

Daughter cells are DIPLOID

HeLa Cells

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.

Article on Henrietta Lacks

1.Name the phases starting at the top.

1.Name the phase2. Identify X3. Identify Y

5. Name the phase

6. Name the phase

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? __________