5.1.5

Question 1

Why is it important for plants to respond to their env?

Answer 1

avoid abiotic stress

avoid herbivory

maximise photosynthesis

help ensure germination

Question 2

What is phototropism?

Answer 2

a plants growth repsonse to light

Question 3

What is + phototropism?

Answer 3

growth towards light

Question 4

Why does + phototropism happen>

Answer 4

to get max light for photosynthesis

Question 5

What part of the plant does positive phototropism happen?

Answer 5

stem tip

Question 6

What is negative geotropism?

Answer 6

growth away from light

Question 7

Where does negative geotropism happen?

Answer 7

root tip

Question 8

Why does negative getropism happen?

Answer 8

less chance of drying out

Question 9

What is geotropism?

Answer 9

plants response to a plants growth response to earths gravitational field strength

Question 10

What is positive geotropism?

Answer 10

plants grow towards gravitational attraction

Question 11

What part of the plant exhibits negative geotropism?

Answer 11

shoots

Question 12

What is hydrotropism?

Answer 12

Plant’s growth response to earth’s water

Question 13

What part of a plant exhibits positive hydroptropism?

Answer 13

respond by growing towards water

Question 14

What is thigmotropism?

Answer 14

plant’s growth response to touch

Question 15

What is the Mimosa Puddica?

Answer 15

responds to to touch

Question 16

What does the mimosa puddica do when touched?

Answer 16

leaves coil up

Question 17

What is benefit of M.P leaves coiling up?

Answer 17

movement of leaves scares away herbivores

curling leaves less likely to be eaten

Question 18

What are alkaloids?

Answer 18

bitter tasting
nitrogenous compounds
plants

Question 19

What is caffeine?

Answer 19

compound
toxic to fungi and insects

Question 20

What is nicotine?

Answer 20

toxin
prod in roots of tobacco plants
poisonous to many insects

Question 21

What are tannins?

Answer 21

bitter-tasting and toxic compound

Question 22

What do tannins do?

Answer 22

bind to digestive enzymes in saliva and inactivate them

Question 23

What does the bitter taste allow?

Answer 23

puts animals off of eating the leaves?

Question 24

What are terpenoids?

Answer 24

large group of compounds produced by plants
form essential oils
often acts as toxins

Question 25

What are pheromones?

Answer 25

chemicals made by organisms that affect behaviour of other species

Question 26

In an auxin exp, what would happen when... tips are removed?

Answer 26

no auxin is made as tip is where auxin is made so no upwards growth of shoot / stems font grow if more developed seedling, more lateral growth (side shoots)

Question 27

In an auxin exp, what would happen when... tips are covered?

Answer 27

auxin moves to all parts of the stem all parts grow

Question 28

In an auxin exp, what would happen when... the tips are lit from one side ?

Answer 28

auxin accumulates on the shaded side causing it to grow more than the illuminated side

Question 29

What is a use of ethene?

Answer 29

control fruit ripening

Question 30

What powder is auxin used in?

Answer 30

rooting

Question 31

What is microppropogation useful for?

Answer 31

produce seedless plants

Question 32

What is micropropogation?

Answer 32

apply root powder to shoots / leaves to stimulate root growth

Question 33

How do auxins stimulate shoot growth?

Answer 33

apical dominance

Question 34

What aids quick growth in shoots?

Answer 34

cytokinnins

Question 35

What is micropropogation?

Answer 35

applied to shoots /leaves of plant to stimulate root growth

Question 36

What are the uses of auxins?

Answer 36

hormonal weedkillers rooting powders

Question 37

How are auxins used as weedkillers?

Answer 37

promotes growth in broad leaved weeds so they cannot support themselves and die so narrow leaved crops can grow without competition

Question 38

What is good about auxins as weedkillers?

Answer 38

cheap less harmful to env

Question 39

What are the uses of gibberelins?

Answer 39

delay ripening / age in fruit produce malt GERMINATION OF SEEDS improves fruit shape and size

Question 40

What do cytokinins do?

Answer 40

prevent ageing in ripened fruit

Question 41

What does a lack of auxin, cytokinins and gibbeilerins cause?

Answer 41

aid fruit dropping

Question 42

What does ethene preserve?

Answer 42

cut flowers and green veg