A scientist applied a waterproof coating to different surfaces of the leaves in three groups of similar plants. The coating blocked any stomata that it covered.
The plants were kept under the same conditions for 6 hours. Any decrease in mass was due to water lost from the leaves.
| Leaf surfaces coated | Mean decrease in mass in 6 hours in g |
|---|---|
| None | 3.8 |
| Upper surface only | 3.4 |
| Lower surface only | 1.0 |
Calculate the reduction in mean mass decrease caused by coating each surface separately, compared with no coating. Use your calculations to explain where most stomata are found and why this distribution is useful to the plant.
74 exam-style questions on AQA GCSE Biology 2.3 Plant tissues, organs and systems, covering 2.3.1 Plant tissues and 2.3.2 Plant organ system. Each one has a worked solution and a mark scheme showing where the marks go.