Describe the changes in the pupil and iris going from A to B in Figure 4 - AQA - GCSE Biology - Question 5 - 2018 - Paper 1
Question 5
Describe the changes in the pupil and iris going from A to B in Figure 4.
Explain how these changes occur.
Refer to the changes in light level in your answer.
Figur... show full transcript
Worked Solution & Example Answer:Describe the changes in the pupil and iris going from A to B in Figure 4 - AQA - GCSE Biology - Question 5 - 2018 - Paper 1
Step 1
Describe the changes in the pupil and iris going from A to B
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Answer
The pupil undergoes dilation as it transitions from A to B in Figure 4. In A, the pupil appears smaller, while in B, it is larger. The iris also changes in response by allowing more light to enter the eye.
Step 2
Explain how these changes occur
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Answer
These changes occur in response to varying light levels. In dim light or low light conditions, as seen in this example, the circular muscles of the iris relax, resulting in the dilation of the pupil. Simultaneously, the radial muscles contract, allowing the pupil to expand.
