A farmer sprays an insecticide on a field of oilseed rape to kill insect pests. The insecticide kills the pests, but the yield of seeds from the crop is lower than expected. Which is the most likely explanation?
The pests made antibodies, so they became immune to the insecticide.
The insecticide also killed insects that pollinate the crop flowers.
The insecticide acted as a fertiliser, so the plants grew too fast.
The insecticide stopped the crop plants from photosynthesising.
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.