In a school experiment, a few students grow plants in pots placed horizontally as shown below. After a few days, the students observed that the roots bent downward, and the shoots curved upward.

(a) Name the tropic movement seen in shoots.

(b) Why do roots always grow downwards?

(c) Which phytohormone regulates the above tropic movements?

(a) Phototropism

(b) Roots grow downward due to positive geotropism. They grow towards the gravitational pull to anchor the plant and absorb water and minerals from the soil.

(c) Auxins