What this practice covers
These questions are drawn from past CIE 9700 Biology papers and filtered to photosynthesis. You answer, you find out immediately whether you were right, and you get the reasoning for the correct option and for each distractor. Wrong answers go to a mistakes locker so you can come back to exactly those.
Practice is free. You need an account only so your progress and your mistakes are still there next time.
Start practising practice questions →
What examiners see students get wrong here
These are the errors that cost marks on photosynthesis, taken from our own topic notes. Read them before you practise and you will recognise the traps in the questions.
- Swapping the two sites, putting the Calvin cycle in the thylakoids or the light-dependent stage in the stroma.
- Saying the light-independent stage happens at night. It happens whenever ATP and reduced NADP are available, which in practice means in the light, and it is called light-independent because light is not used directly.
- Confusing NADP with NAD. Respiration uses NAD and FAD; photosynthesis uses NADP.
- Saying the oxygen released comes from carbon dioxide. It comes from the photolysis of water.
- Describing cyclic photophosphorylation as producing reduced NADP or oxygen. It produces ATP only.
- Confusing an absorption spectrum with an action spectrum, or saying chlorophyll absorbs green light strongly.
- Saying leaves are green because chlorophyll absorbs green light. They are green because it does not.
- Forgetting that five of every six TP are needed to regenerate RuBP, and claiming one turn of the cycle makes a glucose.
Revise it first
If any of the above is unfamiliar, work through the notes before practising: Photosynthesis revision notes.