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4 Alcohol is broken down by liver cells - Edexcel - GCSE Biology - Question 4 - 2022 - Paper 1
Question 4
4 Alcohol is broken down by liver cells. (a) Which process moves alcohol from the blood into the liver cells? A diffusion B respiration C osmosis D transpiration ... show full transcript
Worked Solution & Example Answer:4 Alcohol is broken down by liver cells - Edexcel - GCSE Biology - Question 4 - 2022 - Paper 1
Step 1
Which process moves alcohol from the blood into the liver cells?
Answer
The process that moves alcohol from the blood into the liver cells is diffusion. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, which accurately describes how alcohol enters liver cells.
Step 2
Calculate the difference in risk for these two people when each one drinks 28 units of alcohol per week.
Answer
From Figure 7, when person A (drinking alcohol on its own) consumes 28 units per week, the relative risk of developing cirrhosis is approximately 5. For person B (drinking alcohol with meals), the risk is about 2. Therefore, the difference in risk is:
This means that person A's risk is 3 units higher than person B's risk.
Step 3
Using evidence from Figure 7, state two pieces of health advice for people about drinking alcohol.
Answer
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It is advisable to consume alcohol in moderation and to limit the number of units to less than 28 per week, as higher consumption increases the risk of cirrhosis.
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Consider drinking alcohol with meals, as this can reduce the relative risk of developing cirrhosis compared to drinking alcohol on its own.
Step 4
Step 5
Explain why the scientist is correct regarding person B's genotype being Ff.
Answer
The scientist is correct because person B must have at least one dominant allele (F) since they do not have cystic fibrosis. Additionally, person B must also have a recessive allele (f) since they are not homozygous dominant (FF). Given that person E is ff (homozygous recessive) and person B could have inherited the f allele from person A, it confirms that person B's genotype is Ff.
Step 6