Scientists compared three plants of equal size grown in the same soil conditions.
The table shows differences in the specialised cells of the plants and the mean volumes of water transported in one hour.
| Plant | Mean root hair length in mm | Mean root hair cell wall thickness in µm | End walls between xylem cells | Lignin in xylem walls | Water entering roots in cm³ | Water reaching shoots in cm³ |
|---|---|---|---|---|---|---|
| P | 0.9 | 0.8 | absent | spiral deposits | 4.8 | 4.5 |
| Q | 0.3 | 1.6 | absent | spiral deposits | 2.1 | 2.0 |
| R | 0.9 | 0.8 | many remain | very little | 4.7 | 1.8 |
Explain the differences in the volumes of water transported by plants P, Q and R.
In your answer, identify whether root hair cells or xylem cells are mainly limiting water transport in plants Q and R.
282 exam-style questions on AQA GCSE Biology 1.1 Cell structure, covering 1.1.1 Eukaryotes and prokaryotes, 1.1.2 Animal and plant cells, 1.1.3 Cell specialisation, 1.1.4 Cell differentiation, 1.1.5 Microscopy, and 1.1.6 Culturing microorganisms. Each one has a worked solution and a mark scheme showing where the marks go.