Question

A plant placed near a window bends outward because:

• A. Its tip is able to obtain more light.
• B. Its tip is able to receive necessary warmth.
• C. The auxin content on the shaded side is higher than that on the lighter side and as a result, the shaded side elongate more than the cells on the illuminated side and the tip bends outward.
• D. Its tip is able to get more oxygen.

Answer 1

The correct option is C The auxin content on the shaded side is higher than that on the lighter side and as a result, the shaded side elongate more than the cells on the illuminated side and the tip bends outward.

Light is an important factor influencing plant growth. It is a common observation that plants grow towards the light.

When the plant is kept near the window, the plant moves towards the light source (phototropism).

That transmittable influence is now thought to be the phytohormone auxin.

There is the production of auxin on the opposite side of the plant which is exposed to the sunlight because auxin is light sensitive.

The production of auxin results in cell elongation and bending of the plant in the direction of the sunlight.

Thus, the correct answer is option C.