Unformatted text preview: C. Survey of Plant Hormones III. IV. V. Platns respond to Stimuli A. Gravity 1. Gravitropism 2. Shoot always bends upward (positive) and root curves downward (negative) 3. Statoliths- plastsids containing dense starch grains a. Plants detect gravity by them b. Statoliths aggretgate to the root cap c. There’s more… B. Mechanical Stimuli 1. Thismomorphogenesis- changes in from mechanical stress a. Trees that are in more windy areas have shorter thicker stems than the same species somewhere else b. Rubbing the stems of a young plant changes its growth c. Vines grow straight until they touch something d. Mimosa pudica has closing leafs when it is touched 2. Thigmotropism- directional growth in response to touch 3....
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- Phototropism, Plant Hormones A., Coleptopile, Hormones control plant