B1 - Plant Hormones

Question 0

What is the difference between gravitropism and phototropism?

Answer 0

Gravitropism is the growth of a plant in response to gravity

Phototropism is the growth of a plant in response to light

Question 1

What is auxin?

Answer 1

A plant hormone that stimulates and controls growth in the shoots and roots

Question 2

What would happen to a plant of the tip was cut off and why?

Answer 2

Plant growth will not be controlled and may stop because auxin is made in the tip since the tip is what needs to be controlled

Question 3

Describe the 2 ways that auxin controls growth in the shoots

Answer 3

When the shoot is exposed to light, most of the auxin goes to the side in the shade which makes the cell grow more on the shades side so the shoot bend towards the light

When a shoot is growing sideways, gravity causes the auxin to fall down to the lower side and grow more cells there so the plant bends up

Question 4

Describe the 2 ways that auxin controls growth in the roots

Answer 4

A root growing sideways will have more auxin on the lower side but in a root, auxin prevents growth so the cells in top grow faster so the root bends down

An uneven amount of moisture either side of a root produces more auxin on the side with more moisture stopping growth on that side so the root grows in that direction to get more moisture

Question 5

What are the 2 agricultural uses of plant hormones?

Answer 5

Most seeds in crop fields are broad-leaved where the crops are narrow-leaved. Certain plant hormone weedkillers only affect the broad-leaved weeds, killing them

Plant cuttings don’t always grow in soil so adding hormone rooting powder containing auxin will cause the cuttings to grow as new plants