395 exam-style questions on Form and function with answers and explanations. Six real samples below — the full set is free with an account.
The 'induced fit' model of enzyme action states that:
Answer: The active site changes shape slightly as the substrate binds
In the induced fit model the active site is flexible and moulds around the substrate as it binds, straining bonds and lowering activation energy, unlike the older rigid lock-and-key idea.
Which structure initiates the heartbeat by acting as the heart's natural pacemaker?
Answer: Sinoatrial (SA) node
The sinoatrial node in the right atrium spontaneously generates electrical impulses that spread across the atria, setting heart rate. The AV node then relays the signal to the ventricles.
A defining property of a stem cell is that it
Answer: can self-renew and differentiate
Stem cells retain the capacity to divide (self-renew) and to differentiate; potency varies (totipotent, pluripotent, multipotent).
Active transport across a membrane requires
Answer: energy from ATP
Active transport moves substances against their concentration gradient using ATP and membrane pump proteins.
Facilitated diffusion differs from simple diffusion because it
Answer: uses membrane transport proteins
Facilitated diffusion is passive (down the gradient) but uses channel or carrier proteins for large or polar solutes.
Which pair of bases forms three hydrogen bonds in DNA?
Answer: guanine and cytosine
G–C pairs form three hydrogen bonds; A–T pairs form two. More G–C content therefore raises DNA stability.
That was 6 of 395 Form and function questions.
Practise all 395 freeStateAO1 · 1–2 marks
One word or one short sentence. No explanation, no working: the mark is for the fact itself.
OutlineAO2 · 1–4 marks
A brief account or summary: the main points in two or three sentences, no evaluation.
DistinguishAO2 · 1–4 marks
Make the difference clear for BOTH terms — a definition of one of them is only half an answer.
395 Form and function questions — free with an account. Spaced repetition, streaks and full exam simulations included.
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