One set of muscles in the iris of a person's left eye is damaged and can no longer contract. The right eye is not damaged.
The pupil diameters are measured at two light intensities.
| Light intensity (lux) | Right pupil diameter (mm) | Left pupil diameter (mm) |
|---|---|---|
| 15 | 7.0 | 3.2 |
| 12 000 | 3.0 | 2.8 |
Calculate how much greater the change in diameter is in the right pupil than in the left pupil.
Suggest which set of muscles in the left iris is damaged. Explain your answer using the results.
Explain how the response of the right pupil at the higher light intensity helps to protect the eye.
135 exam-style questions on OCR GCSE Biology 3.1 Coordination and control – the nervous system, covering 3.1.1 Structure of the nervous system, 3.1.2 Coordinated response, 3.1.3 The reflex arc, 3.1.4 Structure of the eye, 3.1.5 Defects of the eye, 3.1.6 Structure and function of the brain, 3.1.7 Difficulties of investigating brain function, and 3.1.8 Limitations in treating nervous system damage. Each one has a worked solution and a mark scheme showing where the marks go.