Phototropism occurs when a plant bends in the direction of a light source. A common light source is the Sun. The plant hormone auxin is released in response to the Sun. What causes the plant to bend toward the light?
A.The hormone auxin causes cells on the shady side of the plant to elongate.
B.The hormone auxin causes cells on the lighted side of the plant to elongate.
C.The hormone auxin causes cells on the shady side of the plant to shrink.
D.The hormone auxin causes cells on the lighted side of the plant to shrink.
Phototropism is most often observed in plants, but can also occur in other organisms such as fungi. The cells on the plant that are farthest from the light have a chemical called auxin that reacts when phototropism occurs.
