Changes in microscope technologySpec 1.3
In short
An electron microscope uses a beam of electrons and has a much higher magnification and resolution than a light microscope. Resolution is how well two points close together can be seen as separate points. Because of this, sub-cellular structures such as ribosomes and the inside of mitochondria can be seen in detail, which has increased understanding of their functions.
Early light microscopes could show cells, but not much detail inside them. Two ideas matter here. Magnification is how many times bigger the image is than the real object. Resolution (resolving power) is how well a microscope can show two points that are close together as separate points.
| Light microscope | Electron microscope | |
|---|---|---|
| Uses | Light and glass lenses | A beam of electrons |
| Magnification | Lower | Much higher |
| Resolution | Lower | Much higher |
| What can be seen | Cells, nucleus, and some larger structures such as chloroplasts | Fine detail, such as the internal structure of mitochondria and chloroplasts, and ribosomes |
Because electron microscopes have a higher magnification and higher resolution, we can see sub-cellular structures in much more detail and with more clarity than in the past. This has increased our understanding of what each structure does, because we can now see how its structure is related to its function.
For a full answer to 'explain how electron microscopes have increased understanding', say three things: higher magnification and resolution, so more detail can be seen, which helps us understand the role of sub-cellular structures.
Written and checked against the Edexcel GCSE Combined Science (1SC0) specification · Updated October 2026