mm, μm and nm, standard form, magnification, scale bars and the two kinds of microscope.
What you will learn
- Convert between mm, μm and nm
- Use magnification = image size ÷ real size
- Work out a real size from a scale bar
Tiny units
1 mm = 1000 μm
1 μm = 1000 nm
1 μm = 1 × 10⁻⁶ m, 1 nm = 1 × 10⁻⁹ m
Cells are tens of micrometres across; ribosomes are about 20 nm. Very small sizes are written in standard form.
The rest of this lesson and its 8 practice questions are locked.
In this lesson
- Tiny units
- Magnification
8 practice questions, marked as you go; about 20 minutes in all.
In this unit: Required practicals and maths skills
The skills behind every biology practical: units and magnification, means and percentages, rates and graphs, sampling, ratios and planning.