1. Cell Growth and Division
Chapter 10

2. Why do cells divide instead of grow indefinitely?

4. 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*

5. 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.

7. The Cell Cycle
Cell cycle

8. Main steps of mitosis: “IPMAT”
Interphase – The cell grows and replicates DNA and centrioles.
Prophase – chromatin wraps up into chromosomes. The nuclear membrane dissolves. Spindle begins to form.
Metaphase – Chromosomes line up in middle. 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.
Cytokinesis – division of cytoplasm

11. Mitosis Lab Microscope Images
Onion Root tip
Low Power

12. Onion Root tip – High Power

13. Whitefish blastula – Low Power

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

15. Phases of mitosis