5.1.5 Plant hormones Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

In plants, hormones are transported by:

A
  • Active transport
  • Diffusion
  • Mass flow (in phloem or xylem)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Hormones affect processes of:

A
  • Cell division
  • Cell elongation
  • Cell differentiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Effect of auxins

A
  • Control cell elongation
  • Prevent abscission
  • Maintains apical dominance
  • Involved in tropisms
  • Stimulates release of ethene
  • Involved in fruit ripening
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Effect of gibberellin

A
  • Causes stem elongation
  • Trigger mobilisation of food stores in seed at germination
  • Stimulation of pollen tube growth in fertilisation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Effect of ethene

A
  • Causes fruit ripening

* Promotes abscission in deciduous trees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Effect of ABA (abscisic acid)

A
  • Maintains dormancy of seeds and buds
  • Stimulates cold protective responses (e.g. antifreeze production)
  • Stimulates stomatal closing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Synergism

A

substances working together –> greater response than when hormones work alone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Antagonism

A

substances have opposite effects; the balance between them determine the response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Steps in seed germination

A

1) Seed absorbs water ⟶ embryo is activated and begins to produce gibberellins
2) Gibberellins stimulate production of enzymes to break down food stores in seed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Monocots (seeds)

A

• Have only 1 seed leaf inside the seed coat

often because endosperm to feed new plant is not inside seed leaf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Dicots (seeds)

A

• Have 2 seed leaves inside the seed coat

usually rounded and fat because they contain endosperm to feed embryo plant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Role of gibberellins in seed germination

A

• Cause synthesis of amylase in seed
⟶ Amylase breaks down starch into glucose for respiration
⟶ Respiration provides energy for growth
⟶ Enabling seed germination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Food store in dicot seeds?

A

Cotyledons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Food store in monocot seeds?

A

Endosperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Endosperm:

A

the food store into monocot seeds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cotyledon:

A

the food store in dicot seeds.

17
Q

What are food stores in seeds used for?

A

• To produce ATP for building materials

⟶ Allows growth and breaking out of seed

18
Q

Testa

A

Seed coat

19
Q

Seed coat

A

Testa

20
Q

Where does growth occur in plants?

A

Meristems ONLY

21
Q

Away from meristems, how can a plant become bigger?

A

The cell can elongate (not divide)

22
Q

Apical meristems are where?

A

at tips of roots and shoots

23
Q

Lateral bud meristems are where?

A

in buds, can give rise to side shoots