Practise 35 exam-style questions on Evidence for evolution for AQA GCSE Biology. Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.
35 questions
2–4 marks each
Instant marking
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20 questions, marked as you go
Sample questions with model answers
Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.
Question 1
2 marks
Why is overuse of antibiotics in agriculture a public health concern?
Model answer
It creates selective pressure for resistant bacteria to evolve; resistant bacteria can spread to humans (through food or environment), reducing effectiveness of antibiotics for treating infections.
Explanation
Widespread antibiotic use accelerates evolution of resistance; this undermines clinical treatment options and poses a public health risk.
Mark scheme
1 mark
selects for antibiotic-resistant bacteria
1 mark
resistant bacteria can spread to humans and reduce antibiotic effectiveness
Question 2
3 marks
Explain why the discovery of DNA inheritance strengthened Darwin's theory of natural selection.
Model answer
DNA explains the mechanism for heritable variation: genes pass traits to offspring; mutations generate new variation; natural selection can act on this heritable variation, producing evolution.
Explanation
Darwin lacked a genetic mechanism; DNA and genes show how traits are inherited and how new variation arises for selection to act upon, supporting the modern synthesis.
Mark scheme
1 mark
DNA (genes) provides mechanism for inheritance of characteristics
1 mark
mutations in DNA create genetic variation
1 mark
natural selection acts on heritable genetic variation to change populations
Question 3
3 marks
Name and briefly describe one molecular technique used to compare genetic material between species.
Model answer
DNA sequencing: determine nucleotide sequence of a gene/genome and compare sequences to calculate similarity and infer relationships; PCR + gel electrophoresis: amplify and compare fragments (e.g., microsatellites) to assess genetic similarity.
Explanation
Sequencing gives direct molecular comparisons; PCR methods can compare presence/size of markers to infer relatedness when sequencing is not used.
Mark scheme
1 mark
DNA sequencing — determine nucleotide sequence
1 mark
compare sequences between species to assess similarity and relationships
1 mark
alternative technique: PCR + gel electrophoresis to compare DNA fragment patterns
Question 4
4 marks
A new drug is being developed from a plant compound. Outline the ethical and practical issues scientists must address before approving it for human use
Model answer
Practical: preclinical safety and efficacy testing, clinical trials (phases), dosage and side-effect profiling, quality control of production; Ethical: informed consent, risk/benefit assessment, animal welfare in testing, access and cost concerns for patients.
Explanation
Drug approval requires rigorous testing to protect patients, and ethical oversight to ensure fair, informed, and humane practices.
Mark scheme
1 mark
preclinical testing and clinical trials to assess safety and efficacy
1 mark
determine dosage and monitor side effects / long-term effects
