Figure 5
(a) (i) An optician tested the eyesight of 240 people - Edexcel - GCSE Biology - Question 4 - 2023 - Paper 1
Question 4
Figure 5
(a) (i) An optician tested the eyesight of 240 people.
35% of these people could read the normal vision row without wearing glasses.
Calculate the number o... show full transcript
Worked Solution & Example Answer:Figure 5
(a) (i) An optician tested the eyesight of 240 people - Edexcel - GCSE Biology - Question 4 - 2023 - Paper 1
Step 1
Calculate the number of people who need glasses to correct their vision.
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Answer
To find the number of people who need glasses, we first calculate 35% of 240:
0.35imes240=84
This means 84 people have normal vision. The remaining people are:
240−84=156
Thus, 156 people need glasses to correct their vision.
Step 2
Which diagram shows how short-sightedness can be corrected?
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Answer
As the diagrams are not provided here, typically the correct diagram would show a lens that helps focus images correctly onto the retina for a person with short-sightedness. This is usually depicted in diagram 'B'.
Step 3
Describe why a person with cataracts would see the image shown in Figure 6.
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Answer
A person with cataracts would see a blurred or distorted image because cataracts cause the lens of the eye to become cloudy. This cloudiness scatters light and prevents it from focusing properly on the retina, resulting in a blurry vision.
Step 4
State the treatment for cataracts.
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The treatment for cataracts typically involves surgical removal of the cloudy lens, which is usually replaced with an artificial lens.
Step 5
Describe how messages are sent from the brain to muscles.
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Answer
Messages are sent from the brain to muscles via motor neurons. When the brain decides to initiate a movement, it sends an electrical signal down the motor neuron. This signal travels along the axon and is transmitted to the muscle fibers at the neuromuscular junction, causing muscle contraction.
