Internal Stimuli
What is internal stimuli?
Internal stimuli is a temporary change in the internal environment of an organism.
What is external stimuli?
It is a change in the environment outside of an organism that influences its behavior
What is turgor pressure?
the water pressure inside the vacuole of the plant cell in response to the force of water within the cell
What is tropism?
It is the turning of all or part of an organism in a particular direction in response to an external stimulus.
What forces can affect motion in plants?
gravity
Examples of internal stimuli in animals
Hunger, fever, or thirst
List examples of external stimuli in animals.
Fight or flight, pupil dilation, migration, hibernation, shivering or sweating, salivating
How does turgor pressure affect plants?
What role does the vacuole play?
If the cells are not swollen by water(no turgor pressure), then the plant will be wilting
If the cells are swollen with water (has turgor pressure), then the plant will be standing up tall
List and define the types of tropisms.
photoropism(light)- plants grow toward the light
geotropism(gravity)- roots grow downward because of gravity
thigmotropism(touch)- plants respond to touch
What does it mean for organisms to “maintain balance”?
the regulation and maintenance of the internal environment of an organism
Examples of internal stimuli in plants
Wilting, dormancy, or turgor pressure
List examples of external stimuli in plants
photoropism(light), geotropism(gravity), thigmotropism(touch),
Why do organisms need to maintain balance? (hint: why do they have responses?)
So that we can adapt and not let little things affect the functioning of our cells
How does an organism’s response to internal stimuli help it maintain balance?
It helps organism maintain normal internal temperature, proper nutrition, and heal from diseases.
How does an organism’s response to external stimuli help it maintain balance?
Helps organism protect itself from predators and/or changing environment conditions. For plants, it helps ensure it gets nutrients it needs to grow (water, sunlight, etc.)
What is a possible consequence if an organism cannot maintain balance?
death