before microscopes people thought you got diseases from curses and supernatural spirits. once microscopes came along scientists discovered microorganisms this enabled them to study cells.

anton van leeuwenhoek was the first person to look at water under a microscope, the microscope he used was a simple light microscope with one lens. compound light microscopes use a series of lenses to magnify objects

there are 3 ideas to the cell theory

1. all organisms are composed of one or more cells

2.the cell is the basic unit of organization of organisms

3.all cells come from preexisting cells

cells that do not contain internal membrane bound structure are called prokaryotic cells

cells containing membrane bound structures are called eukeryotic cells

membrane bound structures within eukaryotic cells are called organelles each organelle has a funcoion that contributes to survival