plants response to stimuli

Question 1

to maximise photosynthesis…

Answer 1

-they sense the direction of light and grow towards

Question 2

what are auxins?

Answer 2

-plant growth hormones

Question 3

where are auxins produced?

Answer 3

-in the tips
-diffuses backwards to stimulate cell elongation process
-which occurs in cells behind tips

Question 4

shoots are…

Answer 4

-positively phototrophic
-negatively geotraphic

Question 5

roots are…

Answer 5

-positively geotropic
-negatively phototropic

Question 6

what happens when a shoot tip is exposed to light?

Answer 6

-accumulates more auxin on side in shade
-cels grow faster on shaded side
-shoot bends towards light

Question 7

what happens when shoot is growing sideways?

Answer 7

-gravity produces unequal distribution of auxin in tip
-causes lower side to grow faster
-bending shoot upwards

Question 8

what happens when ROOTS are growing sideways?

Answer 8

-more auxin in lower side
-in root, extra auxin inhibits growth
-root bends down as there are more cells on top

Question 9

what happens when ROOTS are exposed to some light?

Answer 9

-more auxin accumulates on shaded side
-auxin inhibits cell elongation on the shaded side
-root bends downwards