All organisms are made of cells, the organism's basic unit of structure and function. The microscope's invention and improvement in the seventeenth century led to the discovery and study of cells.
Light microscope Two important concepts in microscopy are magnification and resolving power.
Electron microscope . Instead of light, electron microscopes use electron beams which have much shorter wavelengths than visible light. The upper limits of size are imposed by the surface area to volume ratio. A double membrane which encloses the nucleus in a eukaryotic cell. Long threadlike association of genes, composed of chromatin and found in the nucleus of eukaryotic cells.