An optician tested the eyesight of 240 people - Edexcel - GCSE Biology - Question 4 - 2023 - Paper 1
Question 4
An optician tested the eyesight of 240 people.
35% of these people could read the normal vision row without wearing glasses.
Calculate the number of people who need ... show full transcript
Worked Solution & Example Answer: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, first calculate 35% of the total 240 people:
240×0.35=84
This means 84 people can read normally. The rest need glasses:
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
The correct diagram for correcting short-sightedness is Diagram B. This diagram shows how light rays converge farther away, allowing short-sighted individuals to see more clearly.
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 sees a blurred image because the lens of their eye becomes cloudy. This cloudiness scatters light entering the eye, leading to a distorted image on the retina.
Step 4
State the treatment for cataracts.
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The most common treatment for cataracts is surgical removal of the cloudy lens. The lens is often replaced with an artificial intraocular lens (IOL).
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 through a series of neurons. When a stimulus is detected, the brain sends electrical signals (action potentials) through motor neurons which travel down to the muscle fibers, causing contraction. This process involves neurotransmitters being released at the neuromuscular junction, activating the muscle cells to respond accordingly.
