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The effect of age on focusing distance was investigated - Edexcel - GCSE Biology - Question 4 - 2019 - Paper 1
Question 4
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. The ... show full transcript
Worked Solution & Example Answer:The effect of age on focusing distance was investigated - Edexcel - GCSE Biology - Question 4 - 2019 - Paper 1
Step 1
Calculate the mean distance for the volunteers aged 50.
Answer
To find the mean distance for the volunteers aged 50, we take the distances recorded for the three individuals at age 50 in the provided table. The distances are 292 mm, 301 mm, and 297 mm.
First, we calculate the total distance by summing these values:
Next, we divide the total by the number of individuals (3) to find the mean:
When rounded to three significant figures, the mean distance is:
296 mm.
Step 2
Give one conclusion that can be made from the data in Figure 4.
Answer
One conclusion that can be drawn from the data in Figure 4 is that as the age of the volunteers increases, the focusing distance tends to increase as well. This suggests that older individuals typically require a greater distance to focus clearly on words, indicating a possible decline in near vision with age.
Step 3
Give two improvements that are needed in this investigation before a valid conclusion can be made.
Answer
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Increase sample size: A larger group of volunteers of varying ages should be tested to ensure that the results are representative and statistically significant.
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Control environmental factors: Ensure that external factors such as lighting and font size are consistent during testing to prevent variable results that could affect focusing distance.
Step 4
Describe how light rays are focused to give normal vision.
Answer
Light rays entering the eye are focused by the cornea and the lens. The cornea provides most of the eye's optical power by bending the incoming light rays. The lens fine-tunes the focus by changing its shape, allowing the eye to focus on objects at various distances. This process ensures that light rays converge onto the retina where they are perceived as clear images.
Step 5
Explain which lens would correct the eye defect shown in Figure 6.
Answer
To identify which lens corrects the eye defect shown in Figure 6, we need to examine the direction in which the light rays diverge due to the defect. If the light rays are diverging and not focusing on the retina, a converging lens (lens Y) would be required to bring those rays together so that they focus properly on the retina. Therefore, lens Y is appropriate for correcting the defect.