An engineer tests a warning panel with a volunteer. The panel uses red, green and blue symbols.
The engineer records these observations.
| Test | Light intensity | Observation |
|---|---|---|
| pupil response | 20 lux | pupil diameter = 6.1 mm |
| pupil response | 800 lux | pupil diameter = 2.3 mm |
| colour response | 800 lux | blue symbols are identified correctly, but red and green symbols are repeatedly confused |
The engineer concludes that both responses are controlled by the lens.
Explain whether the engineer's conclusion is correct.
102 exam-style questions on Edexcel GCSE Biology 2.4 The eye, covering 2.4.1 Structure and function of the eye and 2.4.2 Eye defects and their correction. Each one has a worked solution and a mark scheme showing where the marks go.