16.3 Plant responses to herbivory

Question 1

what is herbivory?

Answer 1

when a plant is eaten by a herbivore

Question 2

what are the physical defences a plant may have?

Answer 2

thorns
barbs
spikes
inedible tissue
hairy leaves
stings

Question 3

what are the chemical defences a plant may produce?

Answer 3

tannins
alkaloids
terpenoids

Question 4

tannins

Answer 4

have a bitter taste puts animals off from eating a plant’s leaves

also toxic to insects by inactivating digestive enzymes in an insect’s saliva

Question 5

alkaloids

Answer 5

many act as drugs by affecting the metabolism of predatory animals and poisoning them

can deter or kill

Question 6

terpenoids

Answer 6

act as toxins by interfering with the predator’s nervous system

Question 7

what are pheromones?

Answer 7

chemicals made by an organism which affects the social behaviour of other members

Question 8

how can pheromones be used in plant defence?

Answer 8

they are produced and cause leaves to produce callose to protect the plant from attack

Question 9

what is a VOC?

Answer 9

volatile organic compounds

acts as pheromones between themselves and other organisms

Question 10

when are VOCs produced?

Answer 10

when a plant detects an attack by an insect

Question 11

how does cabbage use VOCs?

Answer 11

they release VOCs when attacked by caterpillars

this attracts parasitic wasps which lay their eggs in the cabbage

eggs hatch and the new parasitic wasps eat the caterpillars

Question 12

which plant folds in response to touch?

Answer 12

Mimosa pudica

Question 13

what happens when Mimosa pudica is touched?

Answer 13

a signal is spread across the whole plant causing the leaves to fold up

Question 14

what does a plant folding do?

Answer 14

scare predators

help knock off any insects on the plant