The diagram shows a cell - Edexcel - GCSE Biology - Question 4 - 2015 - Paper 1
Question 4
The diagram shows a cell.
(a) (i) Complete the sentence by putting a cross (✗) in the box next to your answer.
Structure P is the
A chloroplast
B gene
C ... show full transcript
Worked Solution & Example Answer:The diagram shows a cell - Edexcel - GCSE Biology - Question 4 - 2015 - Paper 1
Step 1
Complete the sentence by putting a cross (✗) in the box next to your answer.
Structure P is the
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Answer
Structure P is the nucleus. The nucleus is the organelle that houses the cell’s genetic material.
Step 2
Complete the sentence by putting a cross (✗) in the box next to your answer.
Structure Q is a
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Answer
Structure Q is a chromosome. Chromosomes are structures within the nucleus that contain genes.
Step 3
State the genetic term used for an alternative form of the same gene.
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Answer
The genetic term for an alternative form of the same gene is allele.
Step 4
Complete the Punnett square to show the possible genotypes of the offspring of Paul and Sue.
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Answer
The completed Punnett square is as follows:
Paul
F f
Sue ---------
F | FF | Ff |
f | Ff | ff |
This shows the possible genotypes: FF, Ff, Ff, and ff.
Step 5
State the probability that Paul and Sue will have a child with cystic fibrosis.
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Since cystic fibrosis is a recessive disorder, a child will have cystic fibrosis if they inherit two copies of the recessive allele (ff). The probability of this occurring is 1 out of 4, or 25%.
Step 6
Explain why a person can be underweight due to cystic fibrosis.
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A person with cystic fibrosis often has difficulties digesting nutrients properly due to thick mucus blocking the pancreas. This leads to malabsorption of nutrients, which can result in underweight or malnourished individuals.
