Name the plant growth hormone which is synthesised at the shoot tip.Explain breifly why does a plant bend towards light during its growth.

The plant growth hormone that is synthesized is the shoot tip is Auxin.

The growth of a plant towards the light source is known as phototropism. It occurs in plants due to the hormone auxin which is highly light sensitive. As sunlight falls on one side of the shoot, auxin gets stimulated and generally it diffuses to the shaded portion of the plant. It starts elongating the cells of the shaded portion. Thus the shaded portion grows and elongates more than the illuminated part. As a result the curvature of the plant stem tip bends towards the light.