The principles and limitations of optical microscopes, transmission electron microscopes and scanning electron microscopes.

Measuring the size of an object viewed with an optical microscope. The difference between magnification and resolution.

Use of the formula: \(\text{magnification}=\dfrac{\text{size of image}}{\text{size of real object}}\)

Principles of cell fractionation and ultracentrifugation as used to separate cell components.

Students should be able to appreciate that there was a considerable period of time during which the scientific community distinguished between artefacts and cell organelles.