QUESTION 130 (5 marks)
Arrows in the food web point from food to consumer. The feeding links shown are the only links considered in this model.
a) Identify the two trophic levels the bird can occupy and justify each using a feeding link. [3 marks]
b) Give one complete food chain in which the hawk occupies level 3 and one in which it occupies level 4. [2 marks]
Practice marking scheme
Answer
Birds can occupy trophic levels 2 and 3. Hawks can occupy levels 3 and 4. Two routes to level 4 are grass → grasshopper → bird → hawk and grass → grasshopper → lizard → hawk.
Working
Grass is the producer at level 1. Birds eating grass are primary consumers, while birds eating grasshoppers are secondary consumers. Hawks eating a grass-feeding bird are secondary consumers at level 3; eating a grasshopper-feeding bird or lizard places them at level 4. A species can participate at different trophic levels through different feeding routes.
Marking criteria
- Identifies bird levels 2 and 3. [1 mark]
- Links level 2 to direct grass consumption. [1 mark]
- Links level 3 to consumption of grasshoppers. [1 mark]
- Gives grass → bird → hawk for level 3. [1 mark]
- Gives grass → grasshopper → bird/lizard → hawk for level 4. [1 mark]
Practice question aligned to the current QCAA syllabus; review the worked solution and marking criteria.
View the QCAA syllabusCompare your working with the guide above.