Ciliated epithelial cells line the airways. What is the function of their cilia?
they absorb oxygen from the air into the blood
they beat to move mucus and trapped dirt away
they produce mucus that traps bacteria and dust
they kill bacteria by releasing digestive enzymes
41 exam-style questions on Edexcel GCSE Biology 1.1 Cells and cell structure, covering 1.1.1 Sub-cellular structures and functions, 1.1.2 Specialised cells and their adaptations, and 1.1.3 Microscope technology and cell structures. Each one has a worked solution and a mark scheme showing where the marks go.