People in a region depend on locally grown sorghum as their main food. A leaf-eating insect pest is already present in the region. Recent winters have been warmer, while the rainfall and area planted with sorghum have not changed.
Why could the warmer winters make this insect pest a greater threat to food security in the region?
The insects may compete with the sorghum for light, reducing photosynthesis in the crop leaves.
More insects may survive between growing seasons, so a larger population damages the sorghum in spring.
The insects may absorb nitrate ions from the soil, leaving fewer mineral ions for the sorghum.
Warmer winters may make the insects resistant to pesticides, so spraying no longer kills them.
127 exam-style questions on OCR GCSE Biology 6.2 Feeding the human race, covering 6.2.1 Biological factors affecting food security, 6.2.2 Agricultural solutions to growing demand, 6.2.3 Selective breeding, 6.2.4 Genetic engineering, 6.2.5 Steps in genetic engineering, 6.2.6 Benefits and risks of gene technology in agriculture, and 6.2.7 Biotechnological solutions to growing demand. Each one has a worked solution and a mark scheme showing where the marks go.