A scientist collects leaf type P and leaf type Q from two habitats. One habitat is dry and exposed to moving air. The other habitat is moist and sheltered.
Equal areas of each leaf type are tested at the same high light intensity, temperature and air movement. Both plants have enough water.
| Measurement | Leaf type P | Leaf type Q |
|---|---|---|
| Mean cuticle thickness (µm) | 3.5 | 14.0 |
| Number of stomata per mm² | 210 | 85 |
| Stomata on lower surface (%) | 62 | 96 |
| Mean leaf thickness (mm) | 0.18 | 0.42 |
| Carbon dioxide uptake (µmol m⁻² s⁻¹) | 13.6 | 7.8 |
| Water loss (g m⁻² h⁻¹) | 210 | 65 |
Using the information in the table, explain which leaf type came from each habitat. Include how the structural measurements account for the carbon dioxide uptake and water loss.
80 exam-style questions on Edexcel GCSE Biology 6.2 Transport in plants, covering 6.2.1 Root hair cell adaptations, 6.2.2 Structure of xylem and phloem, 6.2.3 Transpiration and stomata, 6.2.4 Translocation of sucrose, 6.2.5 Leaf structure for photosynthesis, 6.2.6 Environmental factors on water uptake, 6.2.7 Rate calculations for transpiration, and 6.2.8 Plant adaptations to extreme environments. Each one has a worked solution and a mark scheme showing where the marks go.