5.4 Defences To Herbivory

Question 1

What are some physical defences plants have to prevent them being eaten?

Answer 1

Thorns
Barbs
Spikes
Stings
Spiny leaves

Question 2

(Chemical defences) tannins are compounds called what?

Answer 2

Phenols

Question 3

(Chemical defences) how are phenols defences?

Answer 3

They have a bitter taste

Toxic to insects as they inactivate enzymes in their saliva

Question 4

(Chemical defences) what are rich in tannins?

Answer 4

Tea

Red wine

Question 5

(Chemical defences) alkaloids are bitter tasting compounds found where?

Answer 5

In nitrogenous plants

Question 6

(Chemical defences) alkaloids act as drugs affecting what?

Answer 6

The metabolism of animals

Even poisoning animals

Question 7

(Chemical defences) what are some alkaloids?

Answer 7

Caffeine
Nicotine
Morphine
Cocaine

Question 8

(Chemical defences) caffeine is toxic to what?

Answer 8

Insects

Question 9

(Chemical defences) nicotine is produced where?

Answer 9

Roots of tobacco plants stored in vacuoles

Question 10

(Chemical defences) terpenoids are a large group of compounds forming what?

Answer 10

Essential oils

Question 11

(Chemical defences) terpenoids can be toxins to what?

Answer 11

Insects and fungi attaching the plant

Question 12

(Chemical defences) pyrethrin acts as a neurotoxin doing what?

Answer 12

Interfering with the nervous system if the animals consuming it

Question 13

(Chemical defences) citronella produced by lemon grass acts as what?

Answer 13

Insect repellant

Question 14

(Pheromones) what is a pheromone?

Answer 14

Chemical made by an organism affecting the social behaviour of other members of the same species

Question 15

(Pheromones) plants do not behave socially but sometimes use what?

Answer 15

Pheromones

Question 16

(Pheromones) if a maple tree is attacked by insects what happens?

Answer 16

Releases pheromone absorbed by leaves on other branches

Question 17

(Pheromones) the pheromone absorbed by the leaves causes them to produce what?

Answer 17

Callose to protect them

Question 18

(Pheromones) there is evidence plants can communicate by pheromones in which system?

Answer 18

roots

Telling another plant if they are under water stress

Question 19

(VOCs) what are VOCs?

Answer 19

Volatile organic compounds

Question 20

(VOCs) they act like pheromones between what?

Answer 20

Themselves and other organisms

Question 21

(VOCs) they diffuse where?

Answer 21

Into the air in and around the plant

Question 22

(VOCs) are made when the plant detects and attack by what and how?

Answer 22

Insects

By chemicals in their saliva

Question 23

(VOCs) thought to elicit what?

Answer 23

Gene switching

Question 24

(VOCs) cabbages - attacked by caterpillars produce a chemical signal attracting what?

Answer 24

The parasitic wasp cotesia glomerata

Question 25

(VOCs) cabbages - the wasp lays its eggs where?

Answer 25

Inside caterpillar larva so they are eaten alive when they hatch

Question 26

(VOCs) cabbages - this signal deters other cabbage white butterflies from doing what?

Answer 26

Laying their eggs

Question 27

(VOCs) apples - when apple trees are attacked by spider mites they produce VOCs that do what?

Answer 27

Attract predatory mites that eat the spider mites

Question 28

(VOCs) wheat - some wheat seedlings produce VOCs when attacked by aphids doing what?

Answer 28

Repelling other aphids

Question 29

(Folding) what plant can you see move?

Answer 29

Mimosa pudica

Question 30

(Folding) the mimosa pudica contains toxic alkaloid and its stem has what?

Answer 30

Sharp prickles

Question 31

(Folding) if leaves are touched what do they do?

Answer 31

Fold down and collapse

Question 32

(Folding) what do scientists think this lead folding does?

Answer 32

Scares off large herbivores and dislodges small insects

Question 33

(Folding) how do the plant leaves resume their position so quickly?

Answer 33

Due to movement of potassium ions into cells followed by osmosis