Formative Assessment Probe Review: Is it Food for Plants?

I like this formative assessment because it involves a few of things I like:  plant physiology, science misconceptions, and environmental issues.  Often students do not understand the distinction between plant food and plant nutrients, and products like Miracle Grow help facilitate this misconceptions.  Also, the over-application fertilizers, with the intention of making plants grow larger, can be addressed with this activity.  This activity works toward the realization that sugar produced with the help of photosynthesis is the food for plants.