The movement of sunflower in accordance with the path of the sun is due to:

One of the following plant hormones is responsible for the phenomenon of phototropism in plants. This is:

The movement of a plant part in response to the force of attraction exerted by the earth is called:

The plant part which exhibits negative geotropism is:

A big tree falls in a forest but its roots are still in contact with the soil. The branches of this fallen tree grow straight up (vertically). This happens in response to