Figure shows a specialised cell from the lining of the human windpipe (trachea).
The hair-like structures on the upper surface of the cell beat backwards and forwards. This sweeps mucus, which contains trapped dust and bacteria, up and out of the lungs.
Figure: A specialised cell from the lining of the windpipe

Explain why this cell contains many mitochondria just below its upper surface.
Suggest one piece of evidence from Figure that this cell is specialised.
All the cells in the lining of the windpipe developed from unspecialised cells.
Name the process by which an unspecialised cell becomes a specialised cell.
163 exam-style questions on AQA GCSE Biology 1.1 Cell structure, covering 1.1.1 Eukaryotes and prokaryotes, 1.1.2 Animal and plant cells, 1.1.3 Cell specialisation, 1.1.4 Cell differentiation, 1.1.5 Microscopy, and 1.1.6 Culturing microorganisms. Each one has a worked solution and a mark scheme showing where the marks go.