Module 5: Plant responses to herbivory

Question 1

Common physical defences of plants include …

give 5 examples

Answer 1

-throns
-spikes
-spiny leaves
-fibrous and inedible tissue
-hairy leaves

Question 2

Name the 4 different types of chemical defences

Answer 2

tannins
alkaloids
terpenoids
pheromones ( including VOCs)

Question 3

Make 2 points about how tannins act as a chemical defence

Answer 3

-they have a bitter taste that puts animals off eating the leaves
-they are toxic to insects as they bind to digestive enzymes produced in saliva and inactivate them

Question 4

What are alkaloids?
Many of them act as what?
Give 4 examples of alkaloids

Answer 4

a large group of bitter tasting nitrogenous compounds
many act as drugs as they affect metabolism of animals that take them in and can sometimes poison them
nicotine , caffeine , morphine and cocaine

Question 5

Caffeine is toxic to … (2)

What effect does caffeine have?

Answer 5

insects and fungi

it spreads through soil and prevents germination of seeds of other plants

Question 6

What are terpenoids?

What do they often act as?
Some also can act as …

Answer 6

a large group of compounds produced by plants which often form essential oils
- often act as toxins to insects and fungi
-some also act as insect repellents

Question 7

What is a pheromone?

Answer 7

a chemical made by an organism which affects the social behaviour of other members of the same species

Question 8

Give an example of when a plant may use pheromones to defend itself

make 2 points

Answer 8

if a maple tree is attacked , it releases a pheromone which is absorbed by leaves on other branches

-these leaves then make chemicals such as callose to help protect them if they are attacked

Question 9

Name the chemical produced by plants that act like pheromones but can allow communication between different species

Answer 9

volatile organic compounds

Question 10

What is another response to herbivory that plants can use?

Answer 10

folding in response to touch