A plant breeder investigates the effect of an unknown plant hormone, X. Treatment X is applied before the flowers open.
Some flowers are enclosed in bags that prevent pollen from reaching them. Flowers in the other group are left uncovered and are hand-pollinated.
| Treatment and condition | Number of flowers that developed into fruit | Mean number of seeds per fruit |
|---|---|---|
| No hormone, hand-pollinated | 27 out of 30 | 38 |
| No hormone, enclosed in bags | 0 out of 25 | – |
| Treatment X, enclosed in bags | 36 out of 40 | 0 |
Explain which plant hormone is most likely to be treatment X. Use all the results in the table.
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.