plant hormones Flashcards
what is auxin?
plant growth hormone that controls growth near the tips of shoots and roots
what is photo tropism ?
plant in responses to light
what is gravitropism?
plant responses to gravity
which plant hormone is responsible for fruit ripening and what else soes it stimulate ?
ETHENE
-enzymes that causes fruit to ripen
what are gibberellins important for ?
stimulates seed germination
- stem growth
- flowering
give 3 commercial uses of plant hormones ?
- weed killers
- as rooting powders
- for promoting growth in tissue culture
name the 4 variable to control in the practical investigating plant growth responses ?+how
T-type of seed make sure come from same packet
w-ater using a measuring cylinder to add same amount of water
I-ight intensity keep the same distance between blub and dish the same
N-umber of seed same in each dish
T-emperature keep petri dishes in same temp away from heat sources
what happens if the tip of a root is removed ?
shoot stop growing no auxin available
what happens if there is extra auxin ?
promotes growth in the shoot but inhibits growth in the root…
what happens when SHOOT TIP is exposed to light ?
- more auxin accumulates on the side that’s in the shade
- makes cells grow elongate faster on the shaded side so the shoot bends toward the light
what grows away from gravity ?
-SHOOTS
what happens when a shoot is growing sideways ?
- gravity produces an unequal distribution of auxin in the tip with more on the lower side
- cause side to grow faster on lower side
- resulting the shoot to bend towards the light
what happens when a ROOT grows sideways ?
- will also have more auxin on lower side
- but extra auxin in roots inhibit growth
- means cells on top elongate faster
- roots bends downwards
what grows towards gravity ?
-ROOTS
