1. From One to Trillions

2. What makes a cell? Defined by 2 things- 1.Its genetic code 2.What parts of the genetic code the cell uses

3. What makes a cell? You began as 1 cell with a full genetic code capable of making hundreds of different types of cells Each of your cells still has that full set of instructions!

4. Cell differentiation Each cell HAS full genetic code Each cell does not USE whole genetic code- only uses part of it During cell’s development it is told which instructions to use. Cell then has its directions on how to function

5. New Cells Once a cell is differentiated, it AND all of the cells that cell will split into continue to have that same purpose ex- skin divides to make more skin only!

6. Cells divide? MITOSIS! Mitosis = cell division Why mitosis? 1.Initially- development 2.Now- Growth 3.Now- Repair of damaged tissue

7. When and where? How do cells know? The truly million dollar question- if you can answer that fully, you will be the next instant millionaire! What we know: Partly genetically instructed Partly from chemical signals from neighboring cells.

8. A cell’s lifecycle- Most of cell’s life spent on a small set of functions (looking for disease, producing protein, monitoring for substances, moving bones, etc.) When new cells needed, signal tells cells to STOP functions, to go MITOSIS

9. Mitosis Steps: Pre-mitosis- make copy of each chromosome for new cell. Mitosis: 1.Untangle/coil up DNA 2.Line chromosomes in middle of cell 3.Pull DNA apart 4.Form 2 DNA centers (  nuclei) Prophase Metaphase Anaphase Telophase

14. Results At conclusion, left with 2 new cells One copy of chromosomes went into each cell *2 new cells with identical genetic codes!

15. Fun Facts- Bacterial vs. eukaryotic mitosis- Bacterial- 1,000 b.p. per second! Makes MANY mistakes Eukaryotic- 50 b.p. per second, but happens in many locations at once- takes ONE HOUR for entire human genetic code to be copied far more accurately.