A researcher grew groups of young pepper plants in nutrient solutions containing different concentrations of magnesium ions. All other conditions were kept the same.
After four weeks, the plants supplied with the lowest concentration of magnesium ions had yellow leaves.
| Concentration of magnesium ions in solution in mg/dm³ | Mean chlorophyll content in arbitrary units | Mean increase in dry mass in g |
|---|---|---|
| 2 | 8 | 0.35 |
| 10 | 19 | 0.82 |
| 50 | 31 | 1.46 |
Explain how the results support the conclusion that magnesium ions are needed for plant growth.
133 exam-style questions on AQA GCSE Biology 3.3 Plant disease, covering 3.3.1 Detection and identification of plant diseases and 3.3.2 Plant defence responses. Each one has a worked solution and a mark scheme showing where the marks go.