Topic 5- Plant hormones

Question 1

What is a tropism

Answer 1

A tropism is the response of a plant to a specific stimulus

Question 2

What is phototropism

Answer 2

Phototropism is the reason of a plant’s shoot or root to light

Question 3

What is gravitropism?

Answer 3

Gravitropism is the response of a plant’s shoot or root gravity

Question 4

What is auxin?

Answer 4

Auxin is a hormone which controls the growth of a plant’s shoots or roots. When auxin is unevenly distributed in a growing plant, the rate of growth will also be unequal

Question 5

How do plant shoots show positive phototropism?

Answer 5

-One side of the shoot is in the light, causing auxin to move to the shaded side
-At the shaded side, the cells are stimulated to grow- the shoot bends towards the light
-As a result, photosynthesis can occur at a faster rate

Question 6

How do plants roots show positive gravitropism

Answer 6

-In a horizontal root, auxin accumulates in the lower side, causing cells to grow less
-The root bends in the direction of gravity
-As a result, more water and nutrients are available to the plant roots

Question 7

What are gibberellins

Answer 7

Gibberellins are a type of plant hormone involved in seed germination

Question 8

What is ethene?

Answer 8

Ethene is a type of plant hormone involved in cell division and ripening

Question 9

What are the uses of auxins?

Answer 9

-Weedkillers- auxin causes cells to grows at a rapid rate, causing plant death
-Rooting powder- auxin causes new plant to grow very quickly
- Tissue culture- auxin promotes growth of roots and shoots

Question 10

What are the uses of ethene?

Answer 10

Control of food ripening in the food industry- allows fruit to be ripened just before they are sold

Question 11

What are the uses of gibberellins?

Answer 11

-Termination of seed dormancy
-Promotion of flowering
-Increase of fruit size