PLANT RESPONSES/HORMONES

Question 1

plant responses?

Answer 1

• plants are sensitive to light, water nd the force of gravity. these changes in a plants enviroment are known as stimuli
• a plants growth response to a stimulus is called a tropism
• a plants growth response to light is called a phototropism
• a plants growth response to the force of gravity is called a geotropism

Question 2

a shoot that grows towards light is said to be…?

Answer 2

positively phototropic

Question 3

a root that grows away from light is said to be…?

Answer 3

negatively phototropic

Question 4

A shoot that grows away from the direction of the force of gravity is said to be…?

Answer 4

negatively geotropic

Question 5

A root that grows in the direction of the force of gravity is called…?

Answer 5

positively geotropic

Question 6

where are auxins produced?

Answer 6

auxins are produced in the shoot tip. If the plant is evenly lit on all sides, auxin diffuses down the stem evenly and the plant grows upright

Question 7

where are auxins found?

Answer 7

In uneven lighting more auxins are found on the
shaded side . Auxins promote faster growth on the shaded sided and so curvature of the plant
towards the light source occurs

Question 8

what are auxins?

Answer 8

Plants produce chemicals that regulate growth and development

• These chemicals are plant hormones
• One type of plant hormones are called AUXINS

Question 9

shoots are negativley geotropic?

Answer 9

When a shoot grows sideways, gravity produces an unequal distribution of auxin in the
tip
- With more auxin on the lower side.
- This causes the lower side to grow faster, bending the shoot upwards

Question 10

roots are positively geotropic?

Answer 10

A root growing sideways will also have more auxin on the lower side due to gravity.

• But in the root the extra auxin inhibits growth.
• This means that the top of the root grows faster, and the root bend downwards

Question 11

how does auxin cause the growth of root to occur in different directions?

Answer 11

• auxin gathers on the bottom sied of the root
• the root grows more on the side with the least auxin. this causes the root to grow downwards towards the force of gravity

Question 12

how does auxin cause the growth of shot to occur in different directions?

Answer 12

• auxin gathers on the bottom side of the shoot

- the shoot grows more on the side with the most auxin. this causes the shot to gro upwards towards the light