Scientists use different units to measure the sizes of cells and the structures inside them.
The Table shows some of these units.
Table
| Unit | Symbol | Number of these units in 1 metre |
|---|---|---|
| millimetre | mm\text{mm}mm | 1000 |
| micrometre | 1 000 0001\,000\,0001000000 | |
| nanometre | nm\text{nm}nm |
Give the symbol for micrometre.
Complete the Table by giving the number of nanometres in 1 metre.
A red blood cell is 8 μm8\ \mu\text{m}8 μm wide. Give the width of the red blood cell in nanometres.
A ribosome is much smaller than a red blood cell. State which unit in the Table is the most suitable for measuring the width of a ribosome.
48 exam-style questions on Edexcel GCSE Biology 1.2 Number, size and scale, covering 1.2.1 Number, size and scale with estimations and 1.2.2 Quantitative units in relation to cells. Each one has a worked solution and a mark scheme showing where the marks go.