The table shows pupil diameters measured in one person after allowing the eye to adjust.
Table
| Light intensity / arbitrary units | Pupil diameter / mm |
|---|---|
| 10 | 7 |
| 100 | 5 |
| 1000 | 3 |
Which statement explains the pattern?
The iris increases pupil size as light intensity increases, limiting light entry.
The lens reduces pupil size as light intensity increases, limiting light entry.
The lens increases pupil size as light intensity increases, limiting light entry.
The iris reduces pupil size as light intensity increases, limiting light entry.
42 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.