A bacterial cell is 2 μm2\ \mu\text{m}2 μm long.
Calculate the number of these bacterial cells that would fit end to end along a line 1 mm long.
A virus is 0.05 μm0.05\ \mu\text{m}0.05 μm wide. Give the width of the virus in nm\text{nm}nm.
Calculate how many times longer the bacterial cell is than the width of the virus.
Scientists usually give the sizes of viruses in nanometres rather than in micrometres.
Explain why.
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.