Define phototropism.

Define gravitropism.

Define auxin.

Shoots show a positive         response and a negative         response, so they grow towards light and upwards.

Roots grow downwards to anchor the plant, showing a negative         response and a positive         response.

Where in a plant is auxin mostly made?

How does auxin cause a shoot to bend towards light shining from one side?

How does auxin cause a root to bend downwards in response to gravity?

True or False? A clinostat slowly rotates a plant so that all sides receive equal exposure to light.

True or False? In roots, a higher concentration of auxin increases the rate of cell elongation.

Why is the gravitropism experiment carried out in a light-proof box?