Cells grow in a petri dish tend to divide until they form a thin layer covering the bottom off the dish. If cells are removed from the middle of the dish, the cells bordering the open space will begin dividing until they have filled the empty space. What does this experiment show? i. Cell division is a completely random process
ii. Once cells divide, they never divide again
iii. The controls on cell growth and division can be turned off and on
iv. There is only a limited amount of DNA available to a given group of cells