Developments in Microscopy
Biology: AQA GCSE Higher, topic 1.1.24
Developments in Microscopy
Developments in microscopy (use of the microscope) have allowed us to see smaller details inside cells. This has improved our understanding of cell functions.
Light microscope
- A light microscope passes light through a specimen and creates a magnified image using lenses.
- The first light microscope was made using two lenses towards the end of the 16th century. This microscope had a resolution better than the human eye.
Discoveries using light microscopes
- Light microscopes allowed bacteria to be seen for the first time. They also allowed us to see plant cells and animal cells as separate objects.
- However, we still could not tell lots of sub-cellular (within the cell) structures apart.
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Electron microscope
- The electron microscope was first used in 1933.
- Electron microscopes work in a similar way to light microscopes. However, electrons are passed through the specimen instead of light.
- They can now resolve distances of 1nm (better resolution) with magnifications of ×500,000.
Discoveries using electron microscopes
- The high level of detail of electron microscopes allowed scientists to see sub-cellular structures more clearly.
- They also allowed scientists to study how structures such as mitochondria, chloroplasts and ribosomes function.
Test yourself on Developments in Microscopy
What could scientists see for the first time when they started using light microscopes?
Why could scientists only study how mitochondria, chloroplasts and ribosomes function after electron microscopes were invented?
Why could light microscopes show plant and animal cells as separate objects, but not the sub-cellular structures within them?