1. Reproduction of body (somatic) Cells
The Cell Cycle
Reproduction of body (somatic) Cells
Asexual Reproduction
NO EXCHANGE OF DNA

2. Cell Cycle and Mitosis
Mitosis is the phase of the cell cycle in which cells are reproduced:
Reproduction of cells is necessary for:
Growth of the organism
Repair of damaged cells
This orderly process assures that all of our cells will be identical

3. Chromosomes Chromosomes are on our DNA
They carry all of our genetic information
We have 46 – 23 from each parent
They are in the NUCLEUS of all eukaryotic cells
They float freely in Prokaryotic cells

4. Sister Chromatids These are the chromosomes after they have duplicated
They are exactly the same as each other

5. Interphase The longest phase of the cell cycle
Cells in interphase are performing life functions for the organism

6. Prophase First phase of mitosis –
DNA uncoils and becomes visible under a microscope

7. Metaphase
Chromosomes line up in the center of the cell

8. Anaphase Chromosomes begin to divide –
One of each pair of sister chromatids on each side
Chromatids

9. Telophase/Cytokinesis
The nucleus reforms
Two cells begin to separate
Cytokinesis – two duplicated cells have formed

10. S Phase “S” stands for synthesis – G1 and G2 are GAP phases
DNA is duplicated
G1 and G2 are GAP phases
During G1 the cell grows to normal size
During G2 organelles are formed in preparation for the beginning of mitosis

11. Control
Movement from S phase, G1 and mitosis are controlled by enzymes
Only if new cells are needed, and the cell is healthy will the enzymes activate the cycle to begin

12. CANCER! When the cycle gets out of control, cancer results….
The cycle continues without stopping and a tumor results.
More and more cells become affected by the mutation that caused the cycle to become disturbed

13. P 53 One gene that patrols the cells is the P53 gene
This gene destroys damaged cells so that they will NOT reproduce
Genes are made of proteins
Proteins travel from cell to cell – using Protein channels on the surface of the cell membrane to enter and exit