A farmer grows a crop genetically engineered to resist a herbicide. The farmer sprays the herbicide, killing weeds without killing the crop. Some insects feed only on these weeds.
Which pair of changes is most likely compared with leaving the weeds untreated?
Crop yield decreases through greater competition; weed-feeding insect numbers decrease through food loss.
Crop yield increases through reduced competition; weed-feeding insect numbers increase through food gain.
Crop yield increases through reduced competition; weed-feeding insect numbers decrease through food loss.
Crop yield decreases through greater competition; weed-feeding insect numbers increase through food gain.
44 exam-style questions on AQA GCSE Biology 6.2 Variation and evolution, covering 6.2.1 Variation, 6.2.2 Evolution, 6.2.3 Selective breeding, 6.2.4 Genetic engineering, and 6.2.5 Cloning. Each one has a worked solution and a mark scheme showing where the marks go.