Read Gas exchange in light and dark
This SOF ISO pattern tests identify gases. Read the condition carefully, then use the method below before you solve.
Photosynthesis uses light energy to make food in green plant cells; transport tissues move water and sugar where they are needed.
Track what enters, leaves and moves inside
H₂O rises from roots in xylem · sugar travels from the leaf in phloem
CO₂ enters through stomata; water arrives from roots; oxygen leaves the leaf. Sugar moves from the source leaf to use or storage sites.
Find the tested idea
Write down the quantities, directions or conditions given in the stem before selecting a formula or rule.
Work from the evidence
Use one governing relationship at a time. For a visual question, trace the path; for a numerical question, keep units and signs consistent.
Verify before choosing
Use the wording, diagram and units exactly as given. Select an option only after it satisfies every stated condition.
OlympIQ exam lens
- ✓Extract the condition.
- ✓Apply one governing rule.
- ✓Check sign, unit or direction.
Check the result against a simple limiting case, diagram direction or unit before choosing an option.
Ready to try the pattern?
100% coverage across the linked question.
Practise the linked question