The shorter the wavelength of the illumination, the better is the resolving power. Light rays are measured in nm, and the light microscope has a maximum magnification of about 1,000x, and a resolving power of 0.2 um, while the electron microscope, because of the shorter wavelength of its source of illumination - a beam of electrons, has a resolving power of about 0.2 nm. Using microscopy and other tools, we can distinguish internal structures of cells, and begin to see the internal organizational and structural differences that translate into the diversity of anatomy and function in the cells in an organism. The remaining proteins are coded for by nuclear genes are bacteria-like in size, shape and ribosome type. In single-celled fresh water organisms, e.g., protists, water enters cell by osmosis and accumulates.
Contractile vacuoles collect excess water and pump it out of cell.