A scientist grew four groups of sunflower seedlings in unlabelled nutrient solutions for 21 days.
| Group | Mean height at the start in cm | Mean height after 21 days in cm | Appearance of leaves after 21 days |
|---|---|---|---|
| P | 3.1 | 15.8 | Green |
| Q | 2.7 | 7.1 | Green |
| R | 3.5 | 14.4 | Yellow |
| S | 4.0 | 17.0 | Green |
Which group was most likely grown in a solution deficient in nitrate ions?
Use the data to explain your answer.
Nitrate ions were then added to the solution containing group Q.
Predict what would happen to the rate of growth of the seedlings. Explain your answer.
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.