1. PLANT RESPONSES

2. Read the article and decide for yourself
Do plants have minds?
???
Read the article and decide for yourself

3. Do plants have stress? Do they respond?

4. What are some abiotic stresses faced by plants?
*Turn to a partner
&
list some
abiotic stresses
faced by plants*

5. Abiotic Environmental Stresses
-temperature (too hot, too cold) -amount of sunlight (too much, too little) -water availability (too much, too little) -lack of nutrients in soil -others you came up with??

6. What are some biotic stresses faced by plants?
*Turn to a partner
&
list some
biotic stresses
faced by plants*

7. Biotic Environmental Stresses
predators (omnivores/herbivores)
disease (caused by bacteria, fungi, viruses and/or animals)
competition with other plants
others you came up with??

8. How do plants deal with these stresses?
ADAPTATIONS!

9. Tropisms

10. Tropisms
A tropism is “the turning of all or part of an organism in a particular direction in response to an external stimulus.” It is derived from Greek tropos meaning “turning”

11. Tropisms Can be Positive or Negative
If a plant turns towards the stimulus, then it is a positive tropism. If a plant turns away from a stimulus, then it is a negative tropism.

12. Phototropism
Phototropism is “the orientation of a plant or other organism in response to light, either toward the source of light (positive phototropism) or away from it (negative phototropism).”

13. Positive Phototropisms
Stems exhibit positive phototropism when leaning towards light

14. Negative Phototropisms
Roots exhibit negative phototropism when growing away from the light

15. Gravitropism Gravitropism is
“the growth of a plant or other organism in response to gravity, either being pulled down by gravity (positive gravitropism) or growing against it (negative gravitropism).”

16. Positive Gravitropism
Roots exhibit positive gravitropism when growing down towards gravity

17. Negative Gravitropism
Stems & leaves exhibit negative gravitropism when growing up against gravity

18. Thigmotropisms are growth responses to touch

19. Positive Thigmotropisms
Plant stems (tendrils) exhibit positive thigmotropism when they coil around an object.
Venus fly traps exhibit positive thigmotropism
when they snap shut at the touch of an insect landing inside

20. Negative Thigmotropisms
Roots exhibit negative thigmotropisms when they grow away from or around an object in the soil