1. Stimulus & Response

2. 1.Using the Cornel 2-Column Note Taking System, complete notes over External and Internal Stimulus and Response. 2.Create a foldable in your journal of the 4 tropisms, plus positive and negative tropisms. On the exterior flap, write the name of the tropism, the two inside flaps should include a picture and definition/description with examples.

3. Sneezing Our response when germs and other foreign invaders have entered your body Fever Our bodies raise their temperatures to fight germs and other foreign invaders Animals may vomit to rid themselves of internal contamination

4. Response to Internal Stimuli in Plants

5. REFLEX – an action that is performed without conscious thought as an automatic response to a stimulus. Example: a person moves their leg instantly when the tendon by their knee is struck FIGHT or FLIGHT – an animals response to a threatening situation FIGHT FLIGHT or

6. Plants’ Responses to External Stimuli Growing towards it is the response. The Sun is the stimulus.

7. Turgor Pressure – internal water pressure that prevents wilting and provides support. Changes in turgor pressure are a result of a response to an internal stimuli ----------------------------------------------------------------------------- Tropisms: Growth Responses - Phototropism – growth towards light - Geotropism (also called Gravitropism) – roots grow withgravity – stem away - Hydrotropism – roots grow towards water - Thigmotropism – some plants grow in response to touch ----------------------------------------------------------------------------- Seedling Emergence – seedling stem tip pushes away from gravity to reach sunlight above the ground.

8. Turgor Pressure (low turgor pressure) (high turgor pressure) Phototropism The plant is growing towards the light Stem grows opposite gravity and roots grow with gravity Geotropism & Seedling emergence Hydrodtopism & Thigmotropism

9. Phototropism Time lapse (2 min) Thigmotropism (3 min) http://www.youtube.com/watch?v=tLYOBi5gaVs http://www.youtube.com/watch?v=m2xKjA69j NM Watch the following videos! Keep going….you have one more slide!

10. 1.What comes first? A stimulus or a response? 2.In your own words, define stimulus & response 3.Define internal stimulus. Internal stimulus : a stimulus inside an organism that causes the organism to respond in order to maintain homeostasis. 4.Give an example of an human internal stimulus and what body systems might be involved. 5.How do you think an external stimulus might differ from an internal stimulus? 6.Give a possible example of an external stimulus.