Plant Responses

Question 1

Which is singular/plural between stimuli and stimulus?

Answer 1

sing = stimulus
pl = stimuli

Question 2

What is a stimulus?

Answer 2

anything that causes a reaction in an organism or in any of it’s parts

Question 3

What is a response?

Answer 3

the activity of a cell or organism as a result of a stimulus

Question 4

Name some animal stimuli.

Answer 4

feeling pain/hunger, hearing a noise

Question 5

Name some plant stimuli.

Answer 5

light, temperature, gravity

Question 6

Name some animal responses.

Answer 6

movement, feeding, production of enzymes

Question 7

Name some plant responses.

Answer 7

growth, flowering

Question 8

What 4 structures are needed for response?

(2 of them are only animals)

Answer 8

• chemical/hormonal system (plants and animals)
• nerve and sense organ system (animals)
• method of movement so growth, muscular and skeletal system (animals)
• defence/immune system

Question 9

Growth of flowering plants can be controlled by what two types of factors?

Answer 9

external and internal factors

Question 10

Name 4 external factors for responses in flowering plants.

Answer 10

light
day length
gravity
temperature

Question 11

Give 5 points on light as an external factor for responses in flowering plants.

Answer 11

1) provides energy
2) produce chlorophyll
3) fully formed chloroplasts
4) normal-sized leaves
5) strong stems

Question 12

Describe day length as an external factor for responses in flowering plants.

Answer 12

plays a role in causing plants to flower,
also for fruit and seednformation, dormancy and germination

Question 13

Describe gravity as an external factor for responses in flowering plants.

Answer 13

can cause roots to grown down into soil
and shoots grow upwards away from gravity

Question 14

Describe temperature as an external factor for responses in flowering plants.

Answer 14

affects rate of enzyme reactions/activity, plants also grow faster at higher temperatures

Question 15

Describe internal factors for responses in flowering plants.

Answer 15

produce chemicals called growth regulators, which are produced in the meristematic regions

Question 16

Growth regulators are produced where?

Answer 16

in the meristematic regions

Question 17

Root tip, shoot tip = ?

Answer 17

region

Question 18

Region = ?

Answer 18

root tip, shoot tip

Question 19

Definition of a tropism?

Answer 19

is the growth of a plant in response to a stimulus

Question 20

Definitions of a positive tropism and a negative tropism?

Answer 20

positive = occurs when the growth is TOWARDS the stimulus

negative = occurs when the growth is AWAY from the stimulus

Question 21

Main advantage of tropism is?

Answer 21

they allow plants to obtain more favourable growing conditions

Question 22

Definition of phototropism?

Answer 22

is the growth of a plant in response to LIGHT

Question 23

The growth of a plant in response to LIGHT is called?

Answer 23

phototropism

Question 24

Definition of geotropism?

Answer 24

is the growth of a plant in response to GRAVITY

Question 25

The growth of a plant in response to GRAVITY is called?

Answer 25

geotropism

Question 26

3 benefits of geotropism?

Answer 26

- can anchor plants - absorb more water - absorb minerals

Question 27

2 points on geotropism in relation to how parts of the plant grow?

Answer 27

stems grow away from gravity, roots grow towards gravity

Question 28

Definition of thigmotropism?

Answer 28

is the growth of a plant in response to TOUCH

Question 29

The growth of a plant in response to TOUCH is called?

Answer 29

thigmotropism

Question 30

An example of a climbing plant?

Answer 30

ivy

Question 31

Definition of hydrotropism?

Answer 31

is the growth of a plant in response to WATER

Question 32

The growth of a plant in response to WATER is called?

Answer 32

hydrotropism

Question 33

What type of tropism are climbing plants?

Answer 33

thigmotropism

Question 34

Climbing plants have what special parts? What do they do?

Answer 34

tendrils: wrap around supporting structures

Question 35

Definition of chemotropism?

Answer 35

is the growth of a plant in response to CHEMICALS

Question 36

The growth of a plant in response to CHEMICALS is called?

Answer 36

chemotropism

Question 37

What would positive hydroptropism look like?

Answer 37

roots and pollen tubes grow towards water

Question 38

Definition of a growth regulator?

Answer 38

a chemical that controls the growth of a plant

Question 39

Most growth regulators are produced in ___ amounts where? And....

Answer 39

small amounts in one part of a plant and transported to another part where they cause an effect

Question 40

Most growth regulators are transported how?

Answer 40

by diffusion in vascular tissue (xylem and phloem)

Question 41

Growth regulators can act as what 2 things?

Answer 41

growth promoters, growth inhibitors

Question 42

Definition of a growth promoter?

Answer 42

a chemical that causes increased growth in plants

Question 43

Auxin is a?

Answer 43

plant growth regulator

Question 44

An example of a growth regulator is?

Answer 44

auxin

Question 45

Name an auxin.

Answer 45

IAA

Question 46

Auxin is produced in what 6 places?

Answer 46

meristematic tissue tips of shoots young leaves seeds root tips buds

Question 47

6 functions of auxin?

Answer 47

- inhibit side branches in stems - stimulate stem elongation - stimulate root growth - develop fruit - cause phototropism - cause geotropism

Question 48

Name 4 effects of auxins.

Answer 48

tropisms apical dominance fruit formaiton Root growth

Question 49

Describe tropisms as an effect of auxin.

Answer 49

auxins cause cell elongation and growth/bending

Question 50

Describe apical dominance as an effect of auxin.

Answer 50

slows down the growth of side branches, (if apical bud is removed side branches develop)

Question 51

Describe fruit formation as an effect of auxin.

Answer 51

IAA made in developing seeds, stimulating food to form in the fruit that surrounds the seed

Question 52

Describe root growth as an effect of auxin.

Answer 52

low concentration, IAA causes roots to grow

Question 53

Give 4 points on the role of auxin/IAA in phototropism.

Answer 53

1) IAA produced in growth tips/meritstems of the stem 2) if stem is exposed to light from one side, more IAA will diffuse down the shaded side 3) higher auxin concentration results in more growth 4) as a result of uneven growth, the stem bends towards the light (phototropism will result)

Question 54

What are growth inhibitors?

Answer 54

a chemical that causes a reduction in growth of plants

Question 55

2 examples of growth inhibitors in plants?

Answer 55

ethene abscisic acid

Question 56

Ethene is the only regulator that is?

Answer 56

a gas

Question 57

Ethene is made by plants in what 3 places?

Answer 57

stem nodes, ripe fruits, decaying leaves

Question 58

Give 3 functions of ethene.

Answer 58

- ripening fruits - causing fruit colour to form, fruit flavour to develop and fruit tissues to soften - ageing of plants - stimulating leaves to fall in autumn

Question 59

Ethene is used commercially for?

Answer 59

ripening bananas

Question 60

Abscisic acid is produced in what 3 places?

Answer 60

leaves, stems, root caps

Question 61

2 functions of abscisic acid?

Answer 61

- causing plants to respond to harmful conditions - inhibiting seed germination, allowing seeds to remain dormant in the soil during winter

Question 62

Commercially prepared growth regulators, give 3.

Answer 62

- rooting powders (contain NAA) - seedless fruits - fruit ripening (ethene)

Question 63

Surroundings that are harmful to organism(s) = ?

Answer 63

adverse external environment

Question 64

Plant adaptations for protection consist of what 2 types?

Answer 64

chemical and anatomical/structural

Question 65

Give 2 anatomical/structural protective features.

Answer 65

thorns - blackberry bushes bark - prevent pathogen entry guard cells - shortage of water causes them to shrivel, closing the stomata and reduce further water loss stinging hairs - nettle leaves

Question 66

Give 2 chemical protective features.

Answer 66

chemicals heat shock proteins - surround other proteins and help maintain their shape stress proteins