Mimosa Plants Spread Their Leaflets During the Day and Fold

Multiple Choice

Mimosa plants spread their leaflets during the day and fold them at night. You decide to design an experiment to test whether Mimosa's leaf movements are controlled by a biological clock. Which of the following experiments would be the best test of your hypothesis?

A) Growing the plant indoors and turning the lights on in the middle of the night. If a biological clock is controlling leaf movement, the leaves will open.
B) Putting the plant in a dark closet in the middle of the day. If the leaves close, a biological clock mechanism is ruled out.
C) Subjecting the plant to a flash of red light in the middle of the night. If the leaves open at the usual time the next morning, a biological clock mechanism is ruled out.
D) Putting the plant in a dark closet at nightfall. Check on the plant in the morning about 10 hours later, while the plant is still in the closet. If the leaves are open, a biological clock is indicated.