Question

Phototropism is because of unequal distribution of auxin under the influence of unilateral (one sided) illumination as auxin

• A. Moves from illuminated side to shaded side
• B. Synthesis is checked on illuminated side
• C. Destroyed on illuminated and not on shaded side
• D. All of the above

Answer 1

The correct option is D All of the above

Auxin is a plant hormone that plays important role in phototropism, growth movement in response to light. It promotes cell elongation. It is unequally distributed in the plant cells. It is transported towards the shady side and thus present in higher concentration. However, less auxin is transported towards the illuminated side. Auxin synthesis is inhibited on illuminated side. It moves from the illuminated side to shaded side. Due to this, the plant to grow more on the shaded side and bend in the direction of the light source. It shows phototropic response where faster cell elongation is seen on the shaded side than on the illuminated side.

Thus, the correct answer is option D.