Scientists compare root hair cells from two varieties of the same plant. The root hair cells are otherwise identical, and both varieties are kept under the same conditions.
Each patch of root epidermis has a surface area of 1.00 mm² before the root hairs form.
| Plant variety | Number of root hairs on each patch | Mean surface area added by one root hair in mm² |
|---|---|---|
| J | 160 | 0.020 |
| K | 250 | 0.012 |
Calculate the total absorbing surface area of one patch for each plant variety.
A student predicts that variety K will absorb water faster because it has more root hairs.
Explain whether the student's prediction is supported by the calculated surface areas.
114 exam-style questions on OCR GCSE Biology 2.2 The challenges of size, covering 2.2.1 Exchange surfaces and surface area : volume ratio, 2.2.2 Substances transported in organisms, 2.2.3 The human circulatory system, 2.2.4 The heart and blood vessels, 2.2.5 Red blood cells and plasma, 2.2.6 Uptake of water and mineral ions by plants, 2.2.7 Transpiration and translocation, 2.2.8 Xylem and phloem, 2.2.9 Environmental factors and water uptake, and 2.2.10 Using a potometer. Each one has a worked solution and a mark scheme showing where the marks go.