Summary of plant Hormones Flashcards
1
Q
what are an example of auxins?
A
- IAA
2
Q
Give an example of gibrellins ?
A
- Gibbrellic acid
3
Q
where are auxins made?
A
- root tips
- shoot tips
- young leaves
- growing parts of the plants
4
Q
where are gibrellins made?
A
- seeds
- young leaves
5
Q
where is ethene made?
A
- old leaves
- ripening fruit
6
Q
give an example of absiisic acids?
A
- ABA
7
Q
what causes growth of auxins?
A
- growth in shoots by cell division
8
Q
what promotes gibrellins?
A
- seed germination
- flowering
- stem elongation
- lateral shoot growth
9
Q
what promotes ethene?
A
- leaf loss/drop
- fruit ripening
10
Q
what promotes Abscissic acid?
A
- closing stomata
11
Q
what inhibits auxins?
A
- growth in root tips
- leaf loss
12
Q
what inhibits abscissic aicd?
A
- gibrellins (seed germination)
13
Q
what is the commercial use of auxins?
A
- rooting powders
- weed killers
14
Q
what is the commercial use of gibrellins?
A
- seedless grapes
15
Q
what is the commercial use of ethene?
A
- ripen demands in supermarkets
16
Q
what is the commercial use of abscissic acid?
A
- reduces drought stress
17
Q
What happens in stomata closure?
A
- stomata closes to secure water (transpiration)
- guard cells turgid - open
-ABA binds to receptors in guard cell membrane - open calcium and potassium channels
ions diffuse out of guard cells - increases water potential of guard cells
water will leave the guard cell by osmosis - flaccid - stomata closes
18
Q
explain leaf loss by ethene?
A
- old leaves make ethene
- causes layer of cells in stalk of leave to expand and break
- leaf falls
- water and nutrients
19
Q
Explain seed germination?
A
starch is hydrolysed into glucose in seeds
- glucose is respired (ATP)
- seeds can germinate
