Microscopy and Magnification

This lesson covers microscopy and magnification calculations as required by the Edexcel GCSE Combined Science specification (1SC0). You need to understand the differences between light and electron microscopes, use the magnification formula, and describe how to prepare slides and use a light microscope.

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Why Do We Need Microscopes?

Most cells are too small to see with the naked eye. Microscopes use lenses (or beams of electrons) to produce magnified images of small objects. In biology, microscopes allow us to see the internal structures of cells.

There are two key concepts:

• Magnification — how much larger the image is compared to the real object.
• Resolution — the ability to distinguish between two points that are very close together. Higher resolution means finer detail can be seen.

Exam Tip: Magnification and resolution are different things. A microscope can produce a very large image (high magnification) but if the resolution is low, the image will be blurry and you will not see fine detail.

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Light Microscopes

A light microscope uses visible light and glass lenses to magnify specimens.

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