plant responses

Cards (49)

  • harbivoury plant protection: chemical examples

    tannis
    alkaloids
    terpenoids
    pheromones
    VOC
  • how do tannins protect plants and example of plant that uses them
    bitter taste and toxic to insects. tea leaves contain them
  • how do alkaloids protect plants and example of plant that uses them

    effects ingestors metabolism. plants that use them are coffee (caffeine which prevents germination of fungi and insects) and tobacco (nicotine)
  • how do terpenoids protect plants and example of plant that uses them

    toxic - lemon grass uses them
  • how do pheromones protect plants

    alert it's species to protect themselves
  • how do VOC's protect plants and plant that uses them
    attract preadators preadator - cabbage
  • what does the mimosa padica do for protection
    folds in leaves
  • where is auxin made
    tips of roots and shoots in cells
  • how does auxin help plant growth
    binds to receptors to lower the pH of the membrane to make it optimum temp for enzymes so the wall becomes very elastic so it can stretch more easily and grow
  • what is aptical dominance
    where auxin inhibits the growth of lateral shoots and promotes growth upwards of the tip. lower conc of auxin at the bottom - so more lateral growth
  • how does auxin conc effect growth of plant
    more auxin = more growth until max point where auxin inhibits the growth of a plant
  • experimental evidence for aptical dominance and plant growth effected by auxin:
    when aptical shoot is removed: later shoots grow more at top. plant growth slows and comes to a stop.
  • process of abscission
    - falling light levels means less auxin produced
    - leaves produce ethane to switch on genes to produce enzymes that break down cell walls of separation zones.
    - cells in seperation zones absorb water more easily and swell
    - more strain of leaves and weakens protective layer
    - petiole (stalk) breaks off and leaf falls off
  • effect of gibberellins
    - stimulus seed germination by breaking down food stores to use to make ATP
    - elongates plants by making the internodes bigger
  • experimental evidence for the effect of gibberellins
    - varieties of plant grown with no gibberellins were less likely to germinate and grow short
    - when fungi given gibberellins, they grew long and thin
  • auxin controlling stomata opening and closing:
    soil water levels drop
    plant roots produce ABA which is transported to leaves
    binds to receptors on guard cells
    changes ionic conc of guard cells reducing the water potential
    tutor of cells reduces so stomata close
  • general structure of answer about 'how biotic stress' effects growth
    less photosynthesis
    less glucose
    less respiration
    makes less atp
    less growth
  • what is phototropism
    when plant bends towards unidirectional/unilateral light
  • what is geotropism
    plants effected by gravity (eg roots are positively geotropic)
  • how does auxin control phototropism
    allows more auxin down one side of the plant to elongate it so the plant bends
  • commercial uses of ethene:
    to ripen fruit when u want it
  • commercial uses of auxin:
    micro/propagation to make loads of identical plants
    increases chnace of roots forming
    weed killer - plant grows so much it's unsustainable and dies
  • what is micropropagation
    growing identical plantlets in tissue culture and then planting them out
  • commercial use of gibberellins
    delay ripening of fruit, and improve size and shape of yeild
  • commercial use of cytokinins
    delay fruit aging, control propagation
  • synergism
    working together
  • antagonism
    opposing each other
  • auxins promote ..
    cell elongation
  • gibberellins promote ...
    stem elongation
  • apical
    main stem
  • lateral
    side branches
  • maintaining apical dominance
    auxins favour growth of apical shoots, inhibiting growth of lateral shoots. lateral shoots near the top where auxins are, as you go down less auxins, so longer branches further down
  • 2 types of tropism
    phototropism and geotropism
  • tropisms
    how plants respond to environment changes
  • geotropism
    plants responding to orientation
  • phototropism
    plants respond to light
  • negative phototropism
    plant / roots bend away from light- follow gravity
  • how tropism inhibits growth
    -fruit ripening
    -abscission (leaf falls of stem)
  • what do gibberellins stimulate
    pollen tube growth in fertilisation
  • how do gibberellins promote stem elongation
    increase the length of internodes - beneficial to the plant as taller to reaching light