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b) Macular degeneration is a defect of the eye that occurs when some cells of the retina begin to break down - Edexcel - GCSE Biology - Question 8 - 2016 - Paper 1
Question 8
b) Macular degeneration is a defect of the eye that occurs when some cells of the retina begin to break down. Embryonic stem cell therapy has been used to improve t... show full transcript
Worked Solution & Example Answer:b) Macular degeneration is a defect of the eye that occurs when some cells of the retina begin to break down - Edexcel - GCSE Biology - Question 8 - 2016 - Paper 1
Step 1
Explain how embryonic stem cells could be used to treat macular degeneration.
Answer
Embryonic stem cells have the unique ability to differentiate into various types of cells, including retinal cells. In the context of macular degeneration, these stem cells could be transplanted into the retina to replace damaged or deteriorated cells, potentially restoring vision. Additionally, because embryonic stem cells are pluripotent, they can continue to divide and generate more healthy retinal cells, which may enhance the effectiveness of the treatment over time.
Step 2
Give three ways that the scientist could improve this method to determine if prolonged use of a computer affects reaction time.
Answer
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Increase Sample Size: The scientist could include a larger group of participants to obtain more reliable data and minimize the effects of individual variability.
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Use a Control Group: Having a control group that does not use a computer for three hours would help in comparing and isolating the effects of computer use.
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Vary Computer Tasks: The scientist could have participants engage in different tasks on the computer to assess whether specific activities influence reaction times differently.
Step 3
Calculate the mean reaction time in milliseconds.
Answer
To calculate the mean reaction time:
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First, convert the reaction times from seconds to milliseconds:
- Person 1: 0.258 s = 258 ms
- Person 2: 0.685 s = 685 ms
- Person 3: 0.236 s = 236 ms
- Person 4: 0.246 s = 246 ms
- Person 5: 0.268 s = 268 ms
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Now, sum the reaction times:
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Divide by the number of participants (5):
Step 4