plant response Flashcards
What is a tropism
response of a plant to a directional stimulus
positive tropism is growth towards the stimulus
negative tropism is growth away from the stimulus
What is phototropism
growth of a plant in response to light
What is geotropism
growth of a plant in response to gravity
What is hydrotropism
growth of a plant in response to water
What is thermotropism
growth of a plant in response to temperature
What is thigmotropism
growth of a plant in response to contact with object
What are growth hormones
Hormones that speed up or slow down pant growth
Where are growth hormones produced
growing regions of the plant-shoot tips and root tips
What is gibberellin and what does it do
growth hormone that stimulates seed germination, stem elongation
What are auxins and what do they do
Growth hormones that stimulate growth of shoots by cell elongation
high conc of auxins inhibit growth in roots though
What is indoleacetic acid (IAA)
type of auxin
How does IAA work
moves by diffusion or active transport over short distances and via phloem for long distances
this causes uneven distribution of IAA so uneven growth
moves to shaded region of shoots and roots and causes cell to elongate towards light
What is an apical bud
shoot tip at the top of a flowering plant
what do auxins do to the apical bud
stimulate growth of apical bud and inhibit growth of side shoots from lateral buds-this is called apical dominance
