Plants Flashcards
1
Q
Define tropism
A
Growth movement in response to stimulus
2
Q
Describe negative tropism
A
Growing away from stimulus
3
Q
Describe positive tropism
A
Towards stimulus
4
Q
Describe negative phototropism
A
Growth away from light
5
Q
Describe geotropism
A
Growth away from light
6
Q
Auxin function
A
Promotes growth
7
Q
Causes of tropisms
A
- sunlight breaks down auxin
- area of plant with shade= auxin accumulates
- more growth on shaded side
= lop sided growth
8
Q
Why do plants compete
A
- light and water
- nutrients
- space
9
Q
Define phototropism
A
Shoots growing towards the light
10
Q
Where is auxin produced
A
The tips of the plant
11
Q
Describe how auxin works
A
- light causes auxin to concentrate on the darker side of the shoot tip
- auxin now spreads down the shoot
- cells on darker side grow faster than cells in lighter side
= causes shoot to grow towards light
12
Q
Define geotropism
A
Plants growing towards gravity
(Downwards)
13
Q
Describe how geotropism works
A
- auxin produced at the root
But - gravity causes auxin to concentrate on lower side
= lower side grows more slowly than upper side
14
Q
Use of giberellins
A
Starting the germination of seeds
15
Q
Use of ethene
A
Controls cell division and the ripening of fruits
