Plant Hormones Flashcards
what is phototropism
a plants response to light
what are auxins
hormones in plants that control plant growth and are sensitive to light
where are auxins found
in the tips roots and shoots
what happens during phototropism
auxins move to the more shaded side of the plant and make the cells on the shaded side grow quicker so the shoot bends towards the light
what is gravitropism/geotropism
a plants response to gravity
how are shoots affected by gravity
shoots grow away from gravity as more auxins are on lower side of shoot so lower side grows more
how does gravitropism affect the roots
roots will grow towards gravity as more auxins are on the lower side and in roots auxins stop growth so upper side grows more
what are 3 commercial uses of auxins
killing weeds
growing plants from cuttings
producing new plants from tissue cultures to produce clones
what does gibberellin do
starts off seed germination
give 3 commercial uses of gibberellin
increase fruit size
increase flower production
can ensure all seeds germinate at same time
what is ethene and what does it do
it’s a gas that controls cell division and growth of plants, involved in ripening of fruit
give 1 commercial use of ethene
used to speed up ripening of fruit
first step of light intensity against height of seeds practical
set up 3 peter dishes containing cotton wool soaked in equal volume of water
second step of light intensity against height of seeds practical
put 10 seeds in each petri dish
third step of light intensity against height of seeds practical
out the petri dishes in a warm place and allow to germinate
