A student used a light microscope to look at cells from the inner epidermis of an onion bulb.
Before looking at the cells, the student added a few drops of iodine solution to the slide.
Figure shows the student's drawing of one of the onion cells.
Figure: A student's drawing of one cell from an onion bulb

Suggest why the student added iodine solution to the slide.
Give two pieces of evidence from Figure that show this cell is a plant cell.
The student did not draw any ribosomes.
Suggest why.
The student then looked at a cell from the inside of their own cheek.
Give two sub-cellular structures that the onion cell has but the cheek cell does not have.
139 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.