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The effect of age on focusing distance was investigated - Edexcel - GCSE Biology - Question 10 - 2019 - Paper 1
Question 10
The effect of age on focusing distance was investigated. Volunteers of different ages had their eyes tested. Each volunteer was asked to read words from a book. Th... show full transcript
Worked Solution & Example Answer:The effect of age on focusing distance was investigated - Edexcel - GCSE Biology - Question 10 - 2019 - Paper 1
Step 1
(i) Calculate the mean distance for the volunteers aged 50.
Answer
To calculate the mean distance for the volunteers aged 50, take the recorded distances from the three individuals:
- Person 1: 301 mm
- Person 2: 293 mm
- Person 3: 307 mm
Add these distances together:
Now, divide by the number of individuals (3):
Rounding this to three significant figures, the mean distance is 300 mm.
Step 2
(ii) Give one conclusion that can be made from the data in Figure 16.
Answer
From the data in Figure 16, we can conclude that there is a trend where the mean focusing distance increases with age. Older volunteers tend to have a greater mean distance compared to younger volunteers, indicating a possible decline in near vision ability with age.
Step 3
(iii) Give two improvements that are needed in this investigation before a valid conclusion can be made.
Answer
- Increase the sample size by including more volunteers from each age group to ensure the results are more representative.
- Control environmental factors such as lighting and distance from the book to ensure consistency during testing.
Step 4
Step 5
(c) Describe how light rays are focused to give normal vision.
Answer
In normal vision, light rays enter through the cornea, which refracts (bends) the light. They then pass through the lens, which adjusts its shape to further focus the light onto the retina at the back of the eye. The retina contains photoreceptor cells (rods and cones) that convert the light signals into electrical impulses, which are sent to the brain for visual interpretation.
Step 6
(ii) Explain which lens would correct the eye defect shown in Figure 18.
Answer
To correct the eye defect shown in Figure 18, lens Y would be used. Since the rays are focused in front of the retina, which indicates a need for diverging light rays, lens Y should help by spreading the light rays before they enter the eye, ensuring that they converge correctly on the retina.