This key facts covers Units of Measurement within Microscopy for GCSE Biology. Light and electron microscopes, magnification and resolution calculations, specimen preparation, staining techniques, and practical microscopy skills It is section 7 of 20 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
📐 Units of Measurement
| Unit | Symbol | Equivalent to metres | Conversion | Used for |
|---|---|---|---|---|
| Millimetre | mm | 1 × 10⁻³ m | 1 mm = 1000 μm | Small organisms, large cells |
| Micrometre | μm | 1 × 10⁻⁶ m | 1 μm = 1000 nm | Cells and large organelles |
| Nanometre | nm | 1 × 10⁻⁹ m | 1 nm = 1/1000 μm | Molecules and small organelles |
Quick Conversion Tips:
- mm → μm: multiply by 1000
- μm → nm: multiply by 1000
- μm → mm: divide by 1000
- nm → μm: divide by 1000
Practice questions for Microscopy
What is magnification?
Explain why specimens are stained before viewing under a light microscope.
Quick recall flashcards
What is resolution?
Resolution is the ability to distinguish between two separate points that are close together. It determines how clear and detailed an image is.
What is magnification?
Magnification is how many times larger an image appears compared to the actual object. It tells us how much bigger something looks through a microscope.