A railway company wants to maintain a dense cover of narrow-leaved grass on an earth bank beside a track. Broad-leaved weeds also grow on the bank.
The company tested three methods on equal sections of the bank under otherwise similar conditions. Before the test, broad-leaved weeds covered 40% of each section.
The company will choose a method only if broad-leaved weed cover is below 10% and grass cover is above 75% after six weeks.
| Method | Broad-leaved weed cover after six weeks (%) | Grass cover after six weeks (%) |
|---|---|---|
| No treatment | 42 | 50 |
| Hand pulling | 18 | 64 |
| Auxin weedkiller | 8 | 79 |
Calculate how many times as large the decrease in broad-leaved weed cover was for the auxin weedkiller compared with hand pulling.
Evaluate which method the railway company should use. Use the data and your knowledge of auxins.
105 exam-style questions on Edexcel GCSE Biology 6.3 Plant hormones, covering 6.3.1 Plant hormones and tropisms and 6.3.2 Commercial uses of plant hormones. Each one has a worked solution and a mark scheme showing where the marks go.