Plant responses to herbivory Flashcards Preview

A2 Biology > Plant responses to herbivory > Flashcards

Flashcards in Plant responses to herbivory Deck (6)
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1
Q

What physical defences against herbivory?

A
  • thorns, barbs, spikes, spiny leaves, fibrous and inedible tissue
  • hair leavbes
  • probably just need to spurt out a few of these
    *
2
Q

What are tannins? (chemical responses)

A
  • a phenols
  • produced by many plants
  • make upto 50% of the dry weight of the leaves
3
Q

How are tannins effective against herbivory?

A
  • bitter taste
    • puts animals off
  • toxic to insects
    • bind to digestive enzymes in saliva and inactivate them
  • tea and red wine are both rich in plant tannins
4
Q

What are alkaloids? (chemical defence)

A
  • very bitter tasting
  • nitrogenous compounds found in many plants
5
Q

Hiow are alkaloids effective? What are some examples?

A
  • act as drugs
    • affects metabolism
    • sometimes poisonous
  • caffeine
    • toxic to fungi and insects
    • also spreads through soil, through seedlings, preventing the germination of other plants
      • also stops plant rivals
  • nicotine
    • produced in roots of tobacco plants
    • toxin
    • stored in vacuoles in leaves to be released when the leaf is eaten
6
Q

What are terpenoids? How are they effective?

A
  • large group of compounds produced by plants
  • often form essential oils but act as toxins to insects and fungi that might attack the plant
  • some act as insect repellants

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