All living things are made up of cells inside of the cell is watery and jelly-like. you can't see them just using you eyes. you need a microscope, which makes them look many times bigger that they actually are. a cell can be considered the smallest part of an organism that can survive on its own. some organisms have only one cell, while more complicated organisms are made out of lots of cells. all cells have a membrane, which separates them from the outside world. the membrane protects the cell and allows the cell to be selective about what is allowed in