A student investigated the effect of auxin concentration on the growth of short sections cut from shoots.
The student placed sections of the same starting length in solutions with different concentrations of auxin. The increase in length of each section was measured after 24 hours.
The Table shows the results.
Table
| Auxin concentration in arbitrary units | Trial 1 increase in length in mm\text{mm}mm | Trial 2 increase in length in mm\text{mm}mm | Trial 3 increase in length in mm\text{mm}mm | Mean increase in length in mm\text{mm}mm |
|---|---|---|---|---|
| 0 | 2.0 | 2.4 | 2.2 | 2.2 |
| 1 | 3.6 | 4.2 | 3.9 | 3.9 |
| 2 | 5.4 | 5.0 | 5.8 | X |
| 3 | 5.5 | 5.7 | 5.3 | 5.5 |
Calculate the mean increase in length, X.
Describe the effect of auxin concentration on the increase in length of the shoot sections.
Use data from the Table in your answer.
Explain why the shoot sections increased in length more in the auxin solutions than in the solution with no auxin.
Sections cut from roots were placed in the solution with 2 arbitrary units of auxin. They increased in length less than root sections placed in water.
Explain why.
46 exam-style questions on Edexcel GCSE Biology 6.3 Plant hormones, covering 6.3.1 Plant hormones and tropisms and 6.3.2 Commercial uses of plant hormones. Each one has a worked solution and a mark scheme showing where the marks go.