6.1 Survival and Response Flashcards
1
Q
What is taxes?
A
Simple response which an whole organism will move towards a favourable or away from an unfavourable stimulus
2
Q
What is kinesis?
A
When an organism changes the speed of movement and the rate it changes direction
3
Q
Phototropism in shoots
A
- Promotes cell elongation
- IAA synthesised in shoots
- IAA diffuses into growing regions
- Light causes IAA to go from the light to shaded side
- Higher concentration of IAA on shaded side
- Shaded side elongates
- Shaded side grows fast and shoot bends towards light
4
Q
Phototropism in roots
A
- IAA synthesis in root tips
- Light causes IAA to from from light to shaded side
- Higher concentration of IAA on shaded side
- Cell elongation inhibited on shaded side
- Root cells elongate on lighter side so bends away from light
5
Q
What does IAA cause in shoots?
A
Cell elongation
6
Q
What does IAA cause in roots?
A
Inhibits cell elongation
