This free quiz has all 15 multiple choice questions from Section A of the OCR A Level Biology A Biological Diversity paper (H420/02), November 2021. It marks itself, so you get your score as soon as you finish.
What the multiple choice section covers
Biological molecules: fibrous proteins and recognising molecular structures (2.1.2)
Control of gene expression and the development of body plans (6.1.1)
Antibodies, the primary immune response and autoimmune disease (4.1.1)
Using percentages and proportions to estimate numbers (1.1.3)
DNA sequencing, gel electrophoresis and uses of gene sequencing (6.1.3)
Continuous variation in a plant growth investigation (6.1.2)
Sampling along a transect, species richness and Simpson's Index of Diversity (4.2.1)
How to use it
Section A is worth 15 of the 100 marks in a 2 hour 15 minute paper, so aim to finish it in about 20 minutes and keep the rest of the time for the written questions. The examiners found the multiple choice questions more accessible than in most previous sessions, but noted across the paper that marks were lost when candidates had not taken in all the information given, so read each question stem in full. Paper 2 tests modules 1, 2, 4 and 6, so expect Year 12 and Year 13 content side by side.
Where students lost marks on this paper (from the OCR examiners' report and mark scheme)
These points cover the whole paper, not just the multiple choice section. Each is followed by wording that gained marks.
Describing when asked to outline: Many candidates wrote a detailed description when asked to outline the steps of DNA profiling, and 'use radioactivity' alone was not enough for the probe step.
✔ Gains credit: a concise sequence of PCR amplification, cutting with restriction enzymes, separation by gel electrophoresis, transfer to a membrane, adding a radioactive or fluorescent probe and viewing with X-rays or UV light.
Describing membranes, not explaining: Many candidates described membrane structure instead of explaining how phospholipid structure allows a membrane to form, and some did not make clear which way the molecules face.
✔ Gains credit: the phosphate head is hydrophilic and the fatty acid tails are hydrophobic, so heads face the water or cytoplasm and tails face away from water, forming a bilayer.
Leaving sex out of phenotypes: Most candidates could do the sex-linked cross, but few included the sex of each bird as part of the phenotype.
✔ Gains credit: stating parent and offspring phenotypes with both colour and sex (for example, red male), alongside correct gametes and genotypes using Z and W chromosomes.
Using a chi-squared table: Very few candidates could select a critical value from the statistical table, and few could evaluate a conclusion drawn from a chi-squared result.
✔ Gains credit: choosing the critical value at the 5% level for the correct degrees of freedom, and recognising that a value below the critical value means no significant difference between observed and expected results.
Incomplete natural selection explanations: Level 3 answers on the finch survival data were limited when they did not cover all the key stages or refer precisely to the graph.
✔ Gains credit: pre-existing genetic variation, differential survival of individuals with average beak sizes, and passing on of their alleles to the next generation, supported by accurate use of the data.
Wallace's role in evolution: Very few candidates seemed aware of Wallace's contribution, often linking him to genetics or DNA.
✔ Gains credit: Wallace arrived at similar ideas to Darwin independently, their work was presented or published together, and this added weight of evidence for natural selection.
Stopping at the pioneer community: Answers on succession often discussed only the pioneer community, which was not enough for Level 3.
✔ Gains credit: describing the stages of primary succession with key terms, including the intermediate seral stages, and explaining why heather moorland is an example of deflected succession.
Keep practising
Try the multiple choice sections of the November 2021 AS paper and November 2021 Biological Processes paper, or practise by topic with the Genetics and Evolution, Biodiversity, Communicable Diseases, Cell Structure quizzes. You can also browse all our OCR A Level Biology quizzes. Our OCR A masterclasses (Year 12 on Wednesdays at 5.15pm, Year 13 on Tuesdays at 6.30pm) work through real exam questions on one topic each week.
Practising recall is so important for retention and learning. Try this quiz without books first !
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