A student places oat seedlings in a box where light enters from one side and cress seedlings in a box where light enters evenly from above. After 48 hours, the oat shoots have curved more.
What should the student change so that any difference in shoot curvature can be attributed to the direction of light?
Use cress seedlings in both groups, with even light for both groups
Keep both seed types, but put the cress seedlings in one-sided light and the oat seedlings in even light
Use oat seedlings in both groups, with one-sided light for both groups
Use oat seedlings in both groups, with one-sided light for one group and even light for the other
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.