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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... 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 capability to differentiate into various types of cells in the body, including retinal cells. In the case of macular degeneration, these stem cells can be used to replace the damaged or degenerating retinal cells.
By introducing healthy embryonic stem cells into the retina, there is potential for these cells to integrate into the existing retinal structure and restore function. Additionally, they could promote the repair of other compromised cells around the macula, leading to improved vision for patients suffering from this condition.
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 use a larger group of participants to ensure that the results are statistically significant and representative of the broader population.
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Implement Control Groups: By having a control group that does not use the computer, the scientist can better compare and evaluate the effects of prolonged computer usage on reaction times.
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Vary Testing Times: Conducting tests at different times of the day may also provide information on how reaction times change based on fatigue or daily variations in alertness.
Step 3
Calculate the mean reaction time in milliseconds.
Answer
To calculate the mean reaction time, convert the seconds to milliseconds by multiplying by 1000.
The reaction times are:
- Person 1: 0.258 seconds
- Person 2: 0.685 seconds
- Person 3: 0.236 seconds
- Person 4: 0.246 seconds
- Person 5: 0.268 seconds
Calculations are as follows:
Mean = (0.258 + 0.685 + 0.236 + 0.246 + 0.268) / 5
Mean = 1.693 / 5 = 0.3386 seconds
In milliseconds: 0.3386 seconds * 1000 = 338.6 milliseconds.
Step 4