stimulus & response. stimulus achange in organism’s environment a change in organism’s...
TRANSCRIPT
![Page 1: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/1.jpg)
Stimulus & Stimulus & Response Response
![Page 2: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/2.jpg)
StimulusAA change in organism’s environmentchange in organism’s environment
![Page 3: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/3.jpg)
Types of Stimuli A stimulus can either be external or internal.
External stimuli- come from factors found in the environment.
Examples- temperature, predators, presence of water or food, etc
Internal stimuli- come from factors within an organism
Examples- germs, dehydration, lack of energy, pain
![Page 4: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/4.jpg)
Stimulus
Is this stimulus external or internal?
![Page 5: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/5.jpg)
Response
An organisms reaction to change.
![Page 6: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/6.jpg)
Response
![Page 7: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/7.jpg)
HomeostasisHomeo- sameStasis- state of balance
The purpose of response to stimuli in organisms is to maintain homeostasis, a balance within it’s internal systems.
![Page 8: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/8.jpg)
ExamplesExamples
StimulusStimulus = =
Is this internal or external?Is this internal or external? ResponseResponse = =
StimulusStimulus = =
Is this internal or external?Is this internal or external? ResponseResponse = =
Lack of water
Wilting
Bacteria or Virus
Fever
![Page 9: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/9.jpg)
TropismsTropisms Tropism Tropism = plant’s growth response = plant’s growth response
toward or away from a stimulustoward or away from a stimulus
![Page 10: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/10.jpg)
TropismsTropisms Tropism Tropism = plant’s growth response = plant’s growth response
toward or away from a stimulustoward or away from a stimulus
Positive tropismPositive tropism
Negative tropismNegative tropism
![Page 11: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/11.jpg)
TropismsTropisms Tropism Tropism = plant’s growth response = plant’s growth response
toward or away from a stimulustoward or away from a stimulus
Positive tropismPositive tropism = plant grows toward = plant grows toward a stimulusa stimulus
Negative tropismNegative tropism
![Page 12: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/12.jpg)
TropismsTropisms Tropism Tropism = plant’s growth response = plant’s growth response
toward or away from a stimulustoward or away from a stimulus
Positive tropismPositive tropism = plant grows toward = plant grows toward a stimulusa stimulus
Negative tropismNegative tropism = plant grows away = plant grows away from a stimulusfrom a stimulus
![Page 13: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/13.jpg)
HydrotropisHydrotropismm
HydrotropismHydrotropism = a plant’s = a plant’s
rootsroots grow toward watergrow toward water
Is this positive or negative?Is this positive or negative?
![Page 14: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/14.jpg)
PhototropismPlants grow toward a source of light
Animation:
http://botanical-online.com/animation8.htm
![Page 15: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/15.jpg)
Examples
![Page 16: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/16.jpg)
ThigmotropismA plant grows toward or away from pressure
Positive turns toward pressure
Negative turns away from pressure
![Page 17: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/17.jpg)
Geotropism A plant grows with or against gravity Also called Gravitropism
Negative- A plant’s stems or trunk grow up, against the pull of gravity.
Positive- A plant’s roots grow down, with the pull of gravity
Animation:
http://botanical-online.com/animation4.htm
![Page 18: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/18.jpg)
Regardless of the slope of the land, the tree grows up against gravity.
Regardless of the position a seed is planted in, the roots grow down with gravity and the stem up against gravity.
![Page 19: Stimulus & Response. Stimulus Achange in organism’s environment A change in organism’s environment](https://reader036.vdocuments.net/reader036/viewer/2022062409/5697bf871a28abf838c887f5/html5/thumbnails/19.jpg)
Working Together
Plant tropisms work together to maintain homeostasis within the plant
- geotropism
+ phototropism
+ geotropism
+ hydrotropism