Plan Responses To The Environment

Question 1

Define the term abiotic components

Answer 1

-components of an ecosystem that are non-living

Question 2

What are alkaloids

Answer 2

• organic nitrogen-containing bases that have important physiological effects on animals; including nicotine and morphine

Question 3

Define the term biotic components

Answer 3

-components of an ecosystem that are living

Question 4

What are pheromones

Answer 4

• any chemical substance released by one living thing, which influences the behaviour or physiology of another living thing

Question 5

What are tannins

Answer 5

-phenolic compounds, located in cell vacuoles or in surface wax on plants

Question 6

Define the term tropism

Answer 6

-a directional growth response in which the direction of the response is determined by the direction of the external stimulus

Question 7

What 2 type of external stimuli do plants respond too

Answer 7

-biotic (living) components
-abiotic (non-living) components

Question 8

How does responding to the environment help plants

Answer 8

-aids in them surviving long enough to reproduce

Question 9

What is an example of a way in which plants may respond to an external temperature such as high temperatures

Answer 9

-by depositing thicker layers of was on their leaves

Question 10

What is an example of a way in which plants may respond to an external temperature such as wind

Answer 10

-by making their vascular tissues more lignified

Question 11

What type of response do plants show to herbivores

Answer 11

-chemical defences

Question 12

Name 3 types of chemical defences plants put up to protect themselves from herbivores

Answer 12

1) tannins
2) alkaloids
3) pheromones

Question 13

Name the 4 types of tropisms

Answer 13

1) phototropism
2) geotropism
3) chemotropism
4) thigmotropism

Question 14

Define the term phototropism

Answer 14

-shoots grow towards light, which enables them to photosynthesis

Question 15

Define the term geotropism

Answer 15

-roots grow towards the pull of gravity
- anchors then in the soil and helps them take up water (needed for support) and raw material for photosynthesis and to help cool the plant

Question 16

Define the term chemotropism

Answer 16

-where the growth of a plant is directed by a chemical stimulus
-e.g. on a flower pollen tubes grow down the style, attracted by chemicals, towards the ovary where fertilisation can take place

Question 17

Define the term thigmotropism

Answer 17

-shoots of climbing plants, such as ivy wind around other plants or solid structures to gain support

Question 18

A plant responding towards a stimulus is called what

Answer 18

-a positive tropic response

Question 19

A plant responding away from a stimulus is called what

Answer 19

-a negative tropic response

Question 20

What are non-directional responses to external stimuli called

Answer 20

-nastic responses

Question 21

Where are hormones produced in plants

Answer 21

-by cells in a variety of tissues in the plant

Question 22

How do hormones move around in the plant

Answer 22

-active transport
-diffusion
-mass flow in the phloem sap or in xylem vessels

Question 23

What is the effects of cytokinins in plants

Answer 23

-promote cell division
-delay leaf senescence(aging)
-overcome apical dominance
-promote cell expansion

Question 24

What are the effects of abscisic acid in plants

Answer 24

-inhibits seed germination and growth
-causes stomata closure when the plant is stressed by low water availability

Question 25

What are the effects of auxins in plants

Answer 25

-promotes cell elongation -inhibits growth of side-shoots -inhibits leaf abscission (leaf fall)

Question 26

What is the effect of gibberellins in plants

Answer 26

-promote seed germination and growth of stems

Question 27

What is the effect of ethene on the plant

Answer 27

-promotes fruit ripening

Question 28

Define the term apical dominance

Answer 28

-inhibition of lateral buds further down the shoot by chemicals produced by the apical bud at the tip of a plant shoot

Question 29

What are auxins

Answer 29

-plant hormones which are responsible for regulating plant growth

Question 30

What are gibberellins

Answer 30

-plant hormones which are responsible for control of stem elongation and seed germination

Question 31

What hormone does auxin promote

Answer 31

-abscisic acid

Question 32

What does auxin and abscisic acids mean the plant does

Answer 32

-this helps maintain high abscisic acids levels in buds which reinforces bud dormancy

Question 33

What happens to the amount of abscisic acids when the shoot tip is removed and what does this mean

Answer 33

-there is a drop in abscisic acid which allows for the buds to start forming and forming lateral shoots

Question 34

What do cytokinins override when directly applied to buds and what does this mean

Answer 34

-apical dominance, this means that buds start to grow even if auxins are present

Question 35

What happens to the level of auxin when the apical shoot is removed and what does this mean for cytokinins

Answer 35

-auxin levels drop, which means cytokinins spread more evenly which promotes growth in lateral buds

Question 36

What way do cytokinins travel in a plant, why and what does this mean

Answer 36

-travel to the shoot tip because they are attracted to the auxins and this means that the cytokinins aren’t distributed evenly

Question 37

What triggers gibberellin release in seeds

Answer 37

-absorption of water by the seed

Question 38

Where is gibberellin released from in a germinating seed

Answer 38

-the embryo

Question 40

Where does gibberellin travel after being released

Answer 40

-the aleurone layer in the endosperm

Question 41

What does amylase do in seed germination

Answer 41

-it breaks down starch into glucose

Question 42

How does glucose help the growing embryo

Answer 42

-by providing energy for respiration and is used for protein synthesis

Question 43

What does the cell wall limit the cell’s ability to do in plant cells

Answer 43

-its ability to divide and expand

Question 44

What are meristems

Answer 44

-

Question 45

What limits the cell’s ability to divide and expand

Answer 45

-the plant’s cell wall

Question 46

Where is the only place that growth happens

Answer 46

-where there are groups of immature cells that are still capable of dividing

Question 47

What are groups of cells that are still capable of dividing called

Answer 47

-meristem cells

Question 48

What are apical meristems

Answer 48

-meristems that are eat the tip of roots and shoots and are responsible for the roots and shoots getting longer

Question 49

What are lateral bud meristems

Answer 49

-meristems that are found in the buds and give rise to side shoots

Question 50

What are lateral meristems

Answer 50

-meristems found in the buds and give rise to side shoots

Question 51

What are lateral meristems near the outside of roots and shoots responsible for

Answer 51

-the roots and shoots getting wider

Question 52

What other type of meristem are located between the nodes and what are responsible for

Answer 52

-intercalary meristems -and it is responsible for the shoot getting longer

Question 53

Briefly describe how you could investigate phototrophic and geotropic responses

Question 54

Briefly describe how you could investigate the effect of plant hormones on photoropisms

Question 55

How has the role of auxin as a chemical messenger been confirmed

Answer 55

-agar blocks are impregnated with different concentrations of auxin and gave the same results

Question 56

Where is auxin produced

Answer 56

-at the apex of the shoot

Question 58

What enzyme does gibberellin stimulate the production of

Answer 58

-amylase