A student uses a light microscope to view plant cells.
The microscope has a ×15 \times 15\,×15 eyepiece lens and a ×40 \times 40\,×40 objective lens. Calculate the total magnification of the image of the plant cells seen by the student.
A mitochondrion within one of the plant cells has an actual length of 2.4 μm2.4\text{ }\mu\text{m}2.4 μm. Use your calculated magnification from part (a) to find the length of the mitochondrion's image as seen under the microscope, in micrometres (μm\mu\text{m}μm).
40 exam-style questions on OCR GCSE Biology 1.1 Cell structures, covering 1.1.1 Viewing cells with light microscopes, 1.1.2 Sub-cellular structures and functions, and 1.1.3 Electron microscopy and resolution. Each one has a worked solution and a mark scheme showing where the marks go.