B11.9 + B11.10

Question 1

D. Phototropism?

Answer 1

the response of a plant to light

Question 2

D. Gravitropism?

Answer 2

the response of a plant to gravity ( also known as phototropism)

Question 3

D. Tropisms?

Answer 3

the responses of plant roots and shoots to environmental stimuli such as gravity and light

Question 4

Hormone that controls response of plant to gravity and light?

Answer 4

auxin

Question 5

How does auxin work?

Answer 5

the hormone moves from side of shoot where light is to the unlit side of the shoot and stimulates more growth on the unlit side so the shoot grows towards the light. shoot grows straight when auxin levels are even

Question 6

Effects of auxin on:

• shoots
• roots

Answer 6

• more auxin = more growth

- more auxin = inhibited growth

Question 7

D. Gibberellins?

Answer 7

plant hormone important for initiating seed germination

Question 8

Effect of gibberellins on seeds?

Answer 8

trigger breakdown of food stores in seeds at start of germination
- stimulate growth of plant stems

Question 9

Other use of auxins?

Answer 9

weedkillers - send plant into rapid growth which kills them

Question 10

Uses of ethene in plants?

Answer 10

control fruit ripening - ripen green bananas rapidly after transport so aren’t damaged or overripe

Question 11

Uses of gibberellins?

Answer 11

increase fruit size
end seed dormancy
promote flowering
increase yeild of sugar cane