1. The Cell Cycle
Biology
Ch 10-1 & 10-2

2. All cells come from living cells
Cells reproduce:
To grow
To replace old/injured cells
To increase the SA:V ratio

3. Cell Cycle A continuous series of events: Starts with one cell
Ends with two identical daughter cells

4. Unicellular Organisms
Division of one cell reproduces the entire organism

5. Multicellular Organisms
Division is necessary for growth and repair

6. Remember…
Each of your cells has a complete copy of DNA

7. Genetic Blueprint for Life
DNA
Chromatin
Chromosome
Chromatid
Genetic Information in a Double Helix
DNA wrapped around a protein (histone)
Not visible!
Chromatin condensed into a super coil
Visible!
One half of the Chromosome

8. CHROMOSOME
PROTEIN
DNA
CHROMATID
CHROMATIN

9. Back to the Cell Cycle S
(DNA synthesis) G1
MITOTIC
(M) PHASE G2

10. G1 phase - Interphase First Gap Phase Cell Grows
DNA manufactures proteins
Organelles are produced

11. S phase - Interphase Synthesis Phase DNA is replicated
The longest phase

12. G2 Phase - Interphase Second Gap Phase Cell Grows
Organelles are produced
Final preparations for division

13. LE 12-5
INTERPHASE S G1 M G2
MITOTIC PHASE

14. M phase Mitotic Phase Shortest phase of the cell cycle
Results in two identical daughter cells
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis?

15. G1 checkpoint
Control
system S G1 G2 M
M checkpoint
G2 checkpoint

16. Cell Cycle Checkpoints
Controlled by cyclin:
Enzymes: Cdk
Substrates: Cyclin (protein)