CAIE A Level Biology 9700 · Energy and respiration
Rice (Oryza sativa) is often grown in flooded paddy fields where the roots are submerged. Despite the low oxygen availability in waterlogged soil, rice roots are able to produce ATP to sustain growth. Outline how the roots of rice plants are adapted to produce ATP under waterlogged conditions. In your answer, include the locations and key steps of the respiratory pathway(s) involved, and explain the role of aerenchyma.
7 marks, so the mark scheme is looking for about 7 separate creditworthy points. Making the same point twice in different words earns it once.
Outline means: Give the main points briefly. Less detail than describe, but every key step has to be there. One short line per step, in order. The marks are for coverage, not depth.
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