Photosynthesis - Maple tree
A mature maple tree can have a mass of 1 ton or more (dry biomass, after removing the water), yet it starts from a seed that weighs less than 1 gram. Explain this huge increase in biomass: where did the biomass come from and by what process?
This question is modified from BioDQC (Diagnostic Question Cluster) project.
Here's an example of student thinking revealed by this question. We have used this question in introductory biology courses. Students are presented with a text box in which to write their response to the question prompt.
We recommend that you administer these questions as homework and preface the question with these instructions for students:
"For the following question, please respond to the best of your knowledge and using only the information in the question and what you know. Please do not refer to any outside sources (textbooks, notes, internet, etc.). Any reasonable attempt to answer the question will be awarded full credit."