Three groups of radish seedlings are grown for 12 hours under the same conditions. Each group has its roots in a different nutrient solution.
Solution P and solution Q each contain an auxin concentration that is either higher or lower than the concentration in the reference solution.
| nutrient solution | mean increase in root length in 12 hours / mm |
|---|---|
| reference | 3.0 |
| P | 1.8 |
| Q | 4.2 |
Which statement about the auxin concentrations in P and Q is consistent with these results?
P is lower and Q is higher than the reference
P and Q are both lower than the reference
P is higher and Q is lower than the reference
P and Q are both higher than the reference
105 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.