You wish to test the hypothesis that the gravitropic response is stronger than the phototropic response in stems. How could this hypothesis be tested and what results would be predicted?
Gibberellins are responsible for cell elongation between nodes of a stem. Miniature, or dwarf, varieties of plants have short internode cells. Remembering that a hormone only works after it binds to a receptor protein, propose at least two different hypotheses that could explain why a plant would lack a hormonal response.