5.4 Defences To Herbivory Flashcards Preview

A Level Biology > 5.4 Defences To Herbivory > Flashcards

Flashcards in 5.4 Defences To Herbivory Deck (33):
1

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

Thorns
Barbs
Spikes
Stings
Spiny leaves

2

(Chemical defences) tannins are compounds called what?

Phenols

3

(Chemical defences) how are phenols defences?

They have a bitter taste
Toxic to insects as they inactivate enzymes in their saliva

4

(Chemical defences) what are rich in tannins?

Tea
Red wine

5

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

In nitrogenous plants

6

(Chemical defences) alkaloids act as drugs affecting what?

The metabolism of animals
Even poisoning animals

7

(Chemical defences) what are some alkaloids?

Caffeine
Nicotine
Morphine
Cocaine

8

(Chemical defences) caffeine is toxic to what?

Insects

9

(Chemical defences) nicotine is produced where?

Roots of tobacco plants stored in vacuoles

10

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

Essential oils

11

(Chemical defences) terpenoids can be toxins to what?

Insects and fungi attaching the plant

12

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

Interfering with the nervous system if the animals consuming it

13

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

Insect repellant

14

(Pheromones) what is a pheromone?

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

15

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

Pheromones

16

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

Releases pheromone absorbed by leaves on other branches

17

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

Callose to protect them

18

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

roots
Telling another plant if they are under water stress

19

(VOCs) what are VOCs?

Volatile organic compounds

20

(VOCs) they act like pheromones between what?

Themselves and other organisms

21

(VOCs) they diffuse where?

Into the air in and around the plant

22

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

Insects
By chemicals in their saliva

23

(VOCs) thought to elicit what?

Gene switching

24

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

The parasitic wasp cotesia glomerata

25

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

Inside caterpillar larva so they are eaten alive when they hatch

26

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

Laying their eggs

27

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

Attract predatory mites that eat the spider mites

28

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

Repelling other aphids

29

(Folding) what plant can you see move?

Mimosa pudica

30

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

Sharp prickles

31

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

Fold down and collapse

32

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

Scares off large herbivores and dislodges small insects

33

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

Due to movement of potassium ions into cells followed by osmosis

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