Example Oxbridge interview question: Discuss why you think certain medications (e.g Statins) are given at specific times during the day.

Whilst it is unlikely that an A-level student would be able to give the 'expected' answer to this question, as this would require knowledge of the biological phenomena of circadian rhythms, this question would allow the interviewer to assess the thought processes of the candidate and their ability to reason with the knowledge they have.A logical approach to this question could be to build on the assumption that some medications are given at specific times during the day because they are more efficacious at those timepoints. From this one could suggest several possibilities; each of which could be fleshed out by any further knowledge the pupil has.
Differences in how much drug is absorbed by the body
Differences in how much drug is broken down by the body (metabolised)
Differences in how much drug reaches the target site
Differences in how much of the drug is excreted (e.g at the kidney)
Differences in side effects/toxicities of the drug
Differences in presence/activity of a drug target
Indeed (as some extra knowledge) for the specific example of statins, expression and activity of the enzyme HMG-Coa Reductase (the target of statins) are highest during the night; hence logically giving such medication before sleeping would result in the highest inhibition of cholesterol synthesis (which HMG-Coa Reductase is pivotal for).