A student grew 25 cress seedlings in a box with light coming from one side only.
After three days, 21 of the seedlings had bent towards the light.
Calculate the percentage of seedlings that bent towards the light.
Suggest one reason why some of the seedlings did not bend towards the light.
Describe how the student could measure how much each shoot had bent.
Explain why the student used 25 seedlings rather than one seedling.
Name the hormone that causes the shoots to bend and state where it is made.
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.