Chemicals produced by a plant that control its growth and development are called hormones. → True
A plant's roots grow away from a rock they hit in the soil. This is an example of positive thigmotropism.→ False
Chlorophyll speeds up the rate at which a plant's cells grow and controls a plant's response to light. → False
The critical night length for a certain plant is 10 hours. This plant will flower only when nights are shorter than 10 hours. → False, the plant will flower if the night length is longer than 10 hours.
A plant's adaptation that helps it survive freezing temperatures and lack liquid water is dormancy. → True
The blooming of poinsettias in winter and irises in spring is an example of phototropism. → False, the blooming of poinsettias in winter is as a result of photoperiodism
Plant hormones are chemicals produced by the plant for the control of plant growth and development.
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