1.18-19.Plant Hormones And Their Uses.

Question 1

What is tropism caused by light?

Answer 1

Phototropism.

Question 2

Identify wether plant shoots and plant roots are negatively or positively phototropic.

Answer 2

Plant roots are negatively phototropic.

Plant shoots are positively phototropic to get enough light for photosynthesis.

Question 3

How do auxins cause the plant shoot to grow toward the light?

Answer 3

Auxins cause elongation of the cells and move to the shaded side of the shoot. This makes the cells on the shaded side elongate more causing the shoot to grow toward the light.

Question 4

Auxins in roots cause cells to stop elongating and this causes positive gravitropism.
What does this help the plants roots do?

Answer 4

Helps the plants roots anchor the plants in place and reach moisture underground.

Question 5

What is an example of a selective weed killer?

Answer 5

Artificial auxins that only make plants with broad leaves grow out of control and die. Plants with narrow leaves survive.

Question 6

What does rooting powder do?

Answer 6

Plant cuttings are dipped into rooting powder to make roots develop faster, meaning a larger number of plant can be produced quickly.

Question 7

Name 3 ways in which hormones can control the ripening of fruit.

Answer 7

Hormones can be sprayed on fruit trees to stop fruit from faking and to make it grow bigger.

Can be used to speed up ripening.

Unripen fruit so that they are ripe once they reach their destination.

Question 8

Tropism is responding to stimulus by growing toward or away from it.
Tropism away from stimulus is called…?

Answer 8

Negative tropism