Predict how the coleoptile will grow (or not grow) under each treatment by dragging the labels onto the table. labels may be used once, more than once, or not at all.

The answer is that the Boysen-Jensen experiment demonstrated that a mobile compound produced in the coleoptile tip is required for vertical elongation of the coleoptile in the dark and for bending of the coleoptile in response to directional light. The discovery that this mobile compound could pass through an agar block and still permit elongation in the dark or bending in the light was a key observation that eventually led to the identification of auxin by Frits Went.