A person's pupil remains large when a bright light is shone towards the eye. The lens still focuses normally.
Which explanation best accounts for these observations?
The iris is not responding, so too little light reaches the retina.
The lens is not responding, so too much light reaches the retina.
The iris is not responding, so too much light reaches the retina.
The lens is not responding, so too little light reaches the retina.
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.