⚡ Show all reasoning — the AI marks against the AQA mark scheme. Partial credit for correct biology even if wording differs.
4 marksLimiting factors graphAQA 8461 P2 style
A student measures the rate of photosynthesis of pondweed at different light intensities, first at 15°C and then at 25°C. At low light intensities the two lines are identical, but at high light intensities the 25°C line gives a higher rate. Explain these results. (4 marks)
Hint: Two separate regions to explain: low light (same) and high light (different). Think about which factor is limiting in each region.
+40 XP
4 marksUses of glucoseAQA 8461 style
Glucose produced in photosynthesis can be used in several ways. Describe THREE ways a plant uses glucose, other than respiration. For each, state the purpose. (3 marks)
Hint: Name the molecule glucose is converted to AND explain what it is used for. Three separate points needed.
+40 XP
1 markPhotosynthesis equationAQA 8461 style
Which gas is produced during photosynthesis and used in aerobic respiration?
A Carbon dioxide
B Nitrogen
C Oxygen
D Hydrogen
3 marksStarch test required practicalAQA 8461 style
A student tests a leaf for starch using iodine solution. (a) What colour change indicates starch is present? (b) Why must the leaf be boiled in ethanol first? (c) Why is starch tested rather than glucose? (3 marks)
Hint: (a) Specific colour change. (b) Purpose of ethanol step. (c) Chemical property that makes starch detectable.
A plant is given high light intensity and high CO₂ but the rate of photosynthesis does not increase beyond a certain point. What is most likely to be the limiting factor?