A cabbage plant grows in soil containing nitrate ions. A caterpillar feeds on the leaves of the cabbage plant.
Which route could move nitrogen from the soil into the caterpillar's biomass?
A nitrate ion is absorbed by a root; its nitrogen is used to make amino acids and proteins and enters the caterpillar by feeding.
Nitrogen gas is absorbed by a root; its nitrogen is used to make leaf proteins and enters the caterpillar by feeding.
A nitrate ion is absorbed by a root; the whole ion becomes part of a leaf protein and enters the caterpillar by feeding.
A nitrate ion is changed into nitrogen gas by nitrogen-fixing bacteria; the gas enters the caterpillar during feeding.
101 exam-style questions on Edexcel GCSE Biology 9.3 Material cycles and decomposition, covering 9.3.1 Cycling of materials through ecosystems, 9.3.2 The carbon cycle, 9.3.3 The water cycle, 9.3.4 The nitrogen cycle, 9.3.5 Indicator species and pollution, 9.3.6 Decomposition in preservation and composting, and 9.3.7 Rate changes in decay of biological material. Each one has a worked solution and a mark scheme showing where the marks go.