deathbydesignEAT

- dont commit "cell sucice" - a cancer cell does not kill itself (regular cells kill themselves when they are no longer useful) and therfore continue to divie and make a tumor
 * cancer cells**

- the ultimate unit of life... everything is either a cell or made up by cells - leeuwenhoek- looked at an union and saw that the skin was made up of squares (called them cells) plant cells are squares - animal cells are thin and circular (more like soap bubbles)- cone have walls - talk to eachother, regenerate themselves, heal eachother, move around and kill eachother - cells come together as communities (animals and plants) - can do everything an animal can do - come together to make an organism (like people living in a city) - have to do different jobes in the community - all must get together at the proper place and proper time to form organisms - took nearly 3 billion years for the first multi cellular organisms to come once the first unicellular organisms were present - have to have complex mechanisms inorder to control the behavior of the cells in the organism
 * cells**

- in general they send signals - cancer cells dont listen to the signals - cells dont do anything unless they are signaled to do it    - (divide or dont divide) - a cell only divides when new cells are needed - need signals from other cells to say alive- and if they dont get the signals then they kill themselves - put one cell in a dish- it dies (even with all the food it needs the signals from the other cells) - billions of cells die in you body die within an hour - cells starts PCD when told to die (cancer doesnt listen) - cells first boil, then shrink and compact and then stops moving all together (an "neat" death)- a neighboring cell swallows the cell- then he dectroys the evidence (eats the cell) - we have fingers because the cells inbetween are told to die (leaving us with fingers rather than webs) - development in the brain- 80 or 90% that are made... die- it allows you to match the number of nerve cells to the number of targey cells they have to contact - worm has 959 cells - humans have 1,000,000,000,00,000 - why make a cell if you are going to tell it to die? - probably because that cell has a purpose in an ancestor but not now.
 * how do cells communicate?**