1. Cell Growth and Division
Chapter 10

3. Why do cells divide?
Cells divide to allow the organism to grow and to repair damaged tissue
Cells grow, then divide. Why don’t they keep growing?
Large cells do not have enough DNA to function.
Large cells could not diffuse oxygen and nutrients efficiently. *Agar block lab*

4. Cell division in Prokaryotes and Eukaryotes:
Prokaryotes – single chromosome is copied and the cell splits.
Eukaryotes – All chromosomes must be copied into sister chromatids, held together by a centromere. The copies are then split apart in a process called MITOSIS. The cytoplasm is then split by CYTOKINESIS.

6. The Cell Cycle
Cell cycle

7. Main steps of mitosis: “IPMAT”
Interphase – The cells grows and replicates DNA and centrioles.
Prophase – DNA wraps up into chromosomes. The nuclear membrane dissolves.
Metaphase – Chromosomes line up. Spindle fibers created by the centrioles attach to the centromere..
Anaphase – The spindle fibers will pull the sister chromatids apart
Telophase – chromosomes at opposite ends, the nuclear membrane re-forms.

10. Live video of mitosis:
Cell division
Newt cell division

11. Extra Credit Opportunity…
Create cell models showing all 5 stages of mitosis (IPMAT) and cytokinesis.
Cells must have (where applicable) and labeled:
At least 2 chromosomes
Spindle fibers
Centrioles
Centromeres
Nuclear membrane

12. Mitosis Lab Microscope Images
Onion Root tip
Low Power

13. Onion Root tip – High Power

14. Whitefish blastula – Low Power

15. Whitefish blastula – High Power
What phase is this cell in?

16. Duration of mitosis phases…