plant responses Flashcards
name the uses of auxin in commercial use
herbicides
cuttings
micropropagation
elaborate on the use of auxin in commercial use as a herbicide
stimulates shoot growth (resource using) and inhibits root growth (no resource absorbing) which causes the plant to rapidly grow and exhaust
elaborate on the use of auxin in commercial use in micropropagation
removal of meristems from plant and place in growth medium
how are cuttings grown
cut at lateral buds
cuttings dipped in rooting powder (auxin)
how does auxin herbicide affect narrow-leaf plant
little effect
has little biomass so uses less resouces than broad-leaf plant
why do we grow cuttings
able to clone a plant with desirable traits
saves growing from seed
why do farmers prefer to kill weeds
prevent competition and increase yield
(weeds take up mineral ions and water)
why are synthetic molecules not favourable
not organic and not the exact molecule
what are the uses of gibberellins
seed germination
stem growth
delay senescence - synergetic with auxin
improve shape - charge more
what are the uses of ethene
speeds up ripening - reduces auxin which stops inhibition of ethene, causing ripening
promote fruit drop
promote female sex expression in cucumbers
promote lateral growth
why is lateral growth favourable to farmers
plants sprout more and longer branches, so there will be more flowering buds from which fruit grow
what is a con of ethene
gaseous so can’t control its concentration and don’t know if it’s been evenly distributed across a plant
what are the uses of cytokinins
prevent yellowing
promote cell division and elongation
define synergy
some hormones amplify each other’s effects
define a plant hormone
signalling molecule allows plant to respond to stimuli
what hormone controls stomata closing
Abscisic acid
what is thigmotropism
bend in reponse to touch
how are plant hormones transported
diffusion and vascular bundles
what is a hormone that produces seedless fruit
auxin + gibberellin
what equipment allows a scientist to reduce a gravitropic response
clinostat
describe the inhibition and promotion of growth by auxin
lower conc of auxin = promote root growth first
at a certain point = root growth inhibited and shoot growth promoted
describe seed germination
- water enters endosperm through micropyle
- promotes gibberellin action
- which promotes the transcription of amylase and proteases
- starch and protein stored are broken down
- their products diffuse into the embryo
what are the different layers of the seed called starting from the outer most layer
testa
aleurone
endosperm
