Question

Explain role of auxin in phototropism.

Answer 1

Auxin is a plant growth hormone which present on the tip of the plant.It goes towards shadow when sunlight falls on the tip of the plant and make plant grow from that point and in result plant bends towards the light .
This entire process is called phototropism.

Answer 2

Auxin increases the flexibility of plant cell walls which are the main factor limiting plant cell growth. As a consequence, plant cells tend to grow faster in the presence of auxin. When a plant senses a directional light stimulus it redistributesits auxin molecules to the side that is further away from the light. As a consequence, the plant cells that are further away from the light experience a greater auxin concentration and grow faster, causing the shoot to bend towards the light. This mechanism allows plants to optimize the amount of light they receive in order to increase photosynthesis rates.