AP BIOLOGY

Detailed explanation-1: -Auxins play a role in stimulating directional growth responses. This is the growth of an organism like a plant towards or away from a stimulus in its environment and is otherwise known as a tropism.

Detailed explanation-2: -Auxins are named after the Greek phrase auxein, meaning “to grow” or “to increase.” Auxins play an important role in stimulating directional growth, which is the growth of a plant toward or away from a specific stimulus in its environment. This type of growth response is called tropism.

Detailed explanation-3: -Answer and Explanation: This statement is true. Auxin is a plant hormone that is responsible for many tropisms, including phototropism and geotropism. In phototropism, auxin on the dark side of the stem causes increased growth on this side of the plant, bending the stem towards a light source.

Detailed explanation-4: -Phototropisms. In a stem, the shaded side contains more auxin and grows longer, which causes the stem to grow towards the light. The plant does NOT bend towards the light. It grows because the auxin causes the cells to elongate on the shaded side, so this side grows more.