A scientist removes several equal-sized sections of tissue from the growing region just behind the tip of a pea plant organ. The organ is either a root or a shoot.
Half of the sections are placed in a dilute auxin solution. The other sections are placed in an identical solution without auxin. All other conditions are kept the same.
The table shows the results after 6 hours.
| Solution | Mean increase in length in mm |
|---|---|
| With auxin | 1.2 |
| Without auxin | 3.6 |
Which statement is correct?
The organ cannot be identified because auxin reduces elongation in both roots and shoots.
The organ cannot be identified because auxin controls bending rather than cell elongation.
The tissue was from a root, because added auxin reduced its elongation.
The tissue was from a shoot, because added auxin reduced its elongation.
87 exam-style questions on AQA GCSE Biology 5.4 Plant hormones, covering 5.4.1 Control and coordination and 5.4.2 Use of plant hormones (HT only). Each one has a worked solution and a mark scheme showing where the marks go.