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.
The rest of the people need glasses to... 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.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
First, we need to determine how many people could read the normal vision row without glasses:
240×0.35=84
This means that 84 people can see without glasses. Now, we find the number of people who need glasses:
240−84=156
Therefore, 156 people need glasses to correct their vision.
Step 2
Which diagram shows how short-sightedness can be corrected?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct diagram for correcting short-sightedness is typically diagram A, which shows the use of diverging lenses to move the image onto the retina.
Step 3
Describe why a person with cataracts would see the image shown in Figure 6.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
A person with cataracts sees a blurred image because the cloudy lens scatters light, preventing a clear image from reaching the retina. This results in difficulty focusing and can lead to distorted vision.
Step 4
State the treatment for cataracts.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The standard treatment for cataracts is surgical removal of the cloudy lens, which is often replaced with an artificial lens.
Step 5
Describe how messages are sent from the brain to muscles.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
When a stimulus is detected, an electrical signal is generated in the sensory neurons, which is then transmitted to the spinal cord and up to the brain. The brain processes the information and sends signals back to the skeletal muscles via motor neurons, leading to a coordinated response.
