plant responses

Question 1

why are chemicals so important in coordinating the growth if plants

Answer 1

multicellular and small sa:v so need coord
x appear to hve nervous systems
chemicals can be carriedin plant t.sys and move

Question 2

why are some chemicals described as plant hormones

Answer 2

made in one place and carried through the t.system to another region where they have an effect
inv in control and coord of the plant
analogous to animal hormones

Question 3

explain the importance of multifuntion hormones in a plant

Answer 3

one chemical can exert control in diff ways in diff parts of the plant, allowing for complex coord w/out production of huge amounts of diff chemicals

Question 4

how are plant hormones used to control fruit ripening

Answer 4

ethene inv in natural fruit ripening, climacteric-banannas, tomatoes at desired time
cytokinins and gibberellins to delay

Question 5

why is it commercially imp to control FR

Answer 5

ripe easily dam in t
1c ripe finite life b4 goes off
if t hard, unripe lees likely 2 dam and dx go off

Question 6

name 4 plant hormones with commercial uses

Answer 6

ethene
cytokinins
auxins
gibberellins

Question 7

describe the changes in ethene and co2 prod in tomato as it ripens

Answer 7

Ethene levels rise at rate of approximately 5 µl / kg h–1
from day 2 to day 4 (1); and then remain at a
steady level (1); carbon dioxide levels increase at a rate of approximately 15 ml / kg h–1
from day 2 to
day 4 (1); as ethene levels rise (1); as the ethene levels plateau, the carbon dioxide levels decrease
steadily (1) at a rate of around 5ml / kg h
–1
for 5 days(1)

Question 8

why do cool conditions slow the rate of ripening even if ethene is present

Answer 8

ripening is as a result of enzyme controlled reactions
at lower temps reactions occur more slowly
so ripening occurs more slowly even w/ethene present

Question 9

commercial use of cytokinins

Answer 9

prevent aging of ripened fruit and lettuces

micropropagation to control tissue dev

Question 10

commercial use of GA

Answer 10

delay ripening and aging in fruit to improve size and shape, beer brewing to speed up malting process

Question 11

commercial use of auxin

Answer 11

rooting powders, seedless fruit

Question 12

commercial use of ethene

Answer 12

ripening, promote fruit dropping- cotton, walnuts, cherries

Question 13

propagation

Answer 13

growing new plants from the cells of an original plant

Question 14

microprpagation

Answer 14

large scale propagation

Question 15

what happens if balance of diff plant hormones lost

Answer 15

interuptio of metabolism of whole plant, death

Question 16

why must there be a balance between the diff plant hormones

Answer 16

to enable the plant to grow

Question 17

commercial use for synthetic auxins

Answer 17

hormonal weedkillers

Question 18

how do weeds interfere with crop plants

Answer 18

by competing for light, space, water and minerals

Question 19

suggest what is happening in eth and co2 prod graph

Answer 19

b Initial rise in ethene levels triggers start of ripening process (1); many different reactions take place
to bring about fruit ripening (1); requires a lot of energy so respiration rates increase (1); and so
carbon dioxide levels increase dramatically reflecting increased cellular respiration (1); raised ethene
levels maintain ripening process (1); but reactions gradually slow down as aspects of ripening are
completed so demands on respiration are less so amount of carbon dioxide produced is reduced (1).
Link between metabolic increase in response
to ethene, reflected by increased levels of carbon dioxide must be included.

Question 20

investigating the effects of hormones on plant growth

Answer 20

.

Question 21

synergism and antagonism w/ examples

Answer 21

.

Question 22

abiotic stress

Answer 22

.

Question 23

give an example of an auxin

Answer 23

IAA, indoleacetic acid

Question 24

what does the effect of auxin depend on

Answer 24

its conc and any interactions it has w/ other hormones