Response

Question 1

5 things animals respond to

Answer 1

light
sound
hunger
pain
presence of foreign cells

Question 2

3 ways in which animals respond

Answer 2

movement
production of chemicals (enzymes, hormones)
production of cells eg. lymphohocytes

Question 3

4 things that animals need to carry out a response

Answer 3

sense organs and a nervous system
hormonal system
muscular and skeletal system
immune system

Question 4

5 stimuli that plants respond to

Answer 4

light, gravity, touch, H2O or chemicals

Question 5

2 ways in which plants respond

Answer 5

changing their pattern of growth (growth regulation)

germinating, flowering, becoming dormant

Question 6

what are plant responses due to?

Answer 6

the action of chemicals called growth regulators

Question 7

speed of plant responses

Answer 7

much slower than animal responses

Question 8

4 external factors that regulate the growth in plants

Answer 8

light intensity
day length
gravity
temperature

Question 9

how does light intensity act as a growth regulator

Answer 9

affects the rate of photosynthesis and growth

Question 10

how does day light act as a growth regulator

Answer 10

it varies with the seasons, has major effects on seed germination, flowering, seed dormancy and leaf fall

Question 11

how does gravity act as a growth regulator

Answer 11

it ensures that roots grow downwards and shoots grow upwards

Question 12

how does temperature act as a growth regulator

Answer 12

heat (high temperatures) promotes growth by increasing the rate of enzyme activity

Question 13

main internal factor of growth regulation in plants

Answer 13

the production of chemicals called growth regulators in the meristems

Question 14

Growth regulators

Answer 14

chemicals produced by a plant that control its growth and development

Question 15

how do growth regulators get to where they need to be

Answer 15

they are produced in one part of the plant eg. meristems and they are transported to another part of the plant where they cause a response in vascular tissues

Question 16

comment on the speed of growth regulators

Answer 16

slow acting but with a long-lasting effect

Question 17

what does their effect depend on?

Answer 17

their concentration and the location in the plant in which they act

Question 18

higher concentration of auxin

Answer 18

stimulate growth in shoots and inhibit growth in roots

Question 19

lower concentration of auxin

Answer 19

cause more growth in rots and no effect on shoot growth

Question 20

how do growth regulators interact with each other and give an example

Answer 20

interact with each other in controlling growth and development eg. auxins and gibberellins together promote cell elongation in stem

Question 21

5 commercial uses of plant regulators

Answer 21

rooting powders
tissue culturing 
selective weed killers 
formation of seedless fruits
ripening of fruit

Question 22

explain rooting powders as a commercial use of plant regulators

Answer 22

horticulturists use NAA to promote rooting of stem cuttings

Question 23

explain tissue culturing as a commercial use of plant regulators

Answer 23

small pieces of tissue cut off and grown in an artificial medium. form a callous, treated with a high concentration of auxin, it will form shoots and roots

Question 24

explain selective weed killers as a commercial use of plant regulators

Answer 24

2,4-D a synthetic auxin is used as a selective weed killer. It disrupts normal growth of dicots and doesnt affect monocots

Question 25

explain formation of seedless fruit as a commercial use of plant regulators

Answer 25

auxin is applied to flowers before fertilisation occurs so that the ovary enlarges and develops in a fruit without seeds eg. tomatoes

Question 26

explain ripening of fruit as a commercial use of plant regulators

Answer 26

fruits such as bananas are picked when green. Before they are needed in a shop they are exposed to ethene so they all ripen at the same time

Question 27

IAA

Answer 27

Indoleacetic acid

Question 28

explain IAA

Answer 28

a naturally-occurring auxin often found in plants

Question 29

3 places in the plant in which auxin is produced

Answer 29

apical meristems (shoot tip and root tip) developing seed embryos and fruits young developing leaves

Question 30

5 functions of auxin

Answer 30

Controls: - root and stem growth - cell elongation and differentiation - development of flowers and fruit - apical dominance - responses to external stimuli (tropisms)

Question 31

explain cell elongation as an effect of auxins

Answer 31

weakens cell walls, links between cellulose fibres are broken, can take in H2O by osmosis and elongate basis for tropisms

Question 32

explain fruit developing as an effect of auxins

Answer 32

promotes setting and growth of fruit | produces seedless fruits when sprayed on artificially

Question 33

explain apical dominance as an effect of auxins

Answer 33

auxin diffuses down the stem and inhibits growth of side branches stem grows in length with very few side branches

Question 34

abscisic acid

Answer 34

a plant growth regulator that inhibits growth

Question 35

where is abscisic acid produced

Answer 35

stems leaves and green fruit

Question 36

3 functions of abscisic acid

Answer 36

promotes bud and seed dormancy by slowing down growth inhibits cell division promotes leaf fall

Question 37

tropism

Answer 37

growth response of a plant due to an external stimulus

Question 38

positive tropism

Answer 38

growth towards a stimulus

Question 39

negative tropism

Answer 39

growth away from a stimulus

Question 40

importance of tropisms

Answer 40

to allow plants to have a favourable conditions for growth

Question 41

5 types of tropisms

Answer 41

``` phototropism geotropism thigmotropism hydrotropism chemotropism ```

Question 42

phototropism

Answer 42

growth response of a plant to light from a particular direction stem grows towards light, positively phototrophic

Question 43

geotropism

Answer 43

growth response of a plant to gravity | roots grow downwards, positively geotropic

Question 44

thigmotropism

Answer 44

growth response of a plant to touch

Question 45

hydrotropism

Answer 45

growth response of a plant to water

Question 46

chemotropism

Answer 46

growth response of a plant to chemicals

Question 47

role of auxin in phototropism 3

Answer 47

1. auxin is produced in stem tip and diffuses down the stem 2. if light comes from one direction, the auxin moves away from it 3. unequal growth and bending towards the light

Question 48

4 things that plants must protect themselves against

Answer 48

loss of water overheating being infected by microorganisms being eaten

Question 49

2 ways in which a plant can protect itself

Answer 49

structural or chemical adaptations

Question 50

4 structural adaptations

Answer 50

thick cuticle thorns stinging cells deep roots

Question 51

thick cuticle

Answer 51

reduces water loss

Question 52

thorns

Answer 52

to not be eaten

Question 53

stinging cells

Answer 53

to not be eaten

Question 54

deep roots

Answer 54

to absorb water from deep down in the ground

Question 55

3 chemical adaptations

Answer 55

production of toxic chemicals production of heat-shock proteins production of antimicrobial chemicals