Response+to+stimuli+(maintains+homeostasis)

Samantha- Stimuli is defined as anything in the environment that causes an organism to react. For example, light, temperature, odor, sound, gravity, water, or pressure. Protocol: There are many ways to test whether these unknown substances respond to stimuli. We could pour water on each substance to see how they react to it and observe whether they react in a positive or negative way to the water. We could do this same experiment for many other stimuli also.

Samantha Louis, Collin Burns, and Mia Stern

__**Response to Stimuli**__(maintains homeostasis) September 28, 2010

 * Definition:** Anything in the environment that causes an organism to react.


 * Hypothesis-** By adding one drop of distilled water, .9% of saltwater, and 10% of saltwater to each one of the unknown substances and purple onion we will be able to see the response to stimuli.

Microscope Glass Slide Cover Slip Purple Onion Distilled Water Unknown Substances (A,B,and C) Saltwater- .9% and 10% Dropper
 * Materials:**


 * Procedure:**


 * 1) Set up a microscope.
 * 2) Cut a piece of purple and onion and peel a layer of skin off.
 * 3) Place on glass slide.
 * 4) Place a drop of distilled water on the onion and cover with a slip.
 * 5) Place under microscope and observe.
 * 6) Dab off water and place a drop of .9% of salt water on purple onion.
 * 7) Cover with slip and observe.
 * 8) Dab off water and place a drop of 10% salt water on purple onion.
 * 9) Remove purple onion and clean slide.
 * 10) Add substance A on slide.
 * 11) Place one drop of distilled water and then place cover slip on.
 * 12) Place under microscope and observe.
 * 13) Dab off distilled water and put one drop of .9% saltwater on substance A.
 * 14) Place and observe under microscope.
 * 15) Dab off saltwater and put one drop of 10% saltwater on substance A
 * 16) Place and observe under microscope.
 * 17) Remove substance A and clean slide
 * 18) Repeat steps 10 through 17 with substances B and C

__**Observations**__

__Purple Onion:__ **Distilled water-** Cells are large and somewhat defined. - Purple pigment is spread out through the cells.

- Purple pigment is less spread out.
 * .9% Saltwater-** Cells are more defined but smaller.

- larger in size - pigment is in one spot, instead of spread out across the cells
 * 10% Saltwater**- Cells are defined.



__Substance A:__ **Distilled water**-Substance appears to be gray when it is under the microscope -Some darker spots than others -Some more condensed blobs than others


 * .9% Saltwater**- Able to get a clearer visual of cell structure


 * 10% Saltwater**- More defined cell structure



__Substance B:__ **Distilled water**- looks like gray blob




 * .9% Saltwater**- Slowly melted/dissolved when saltwater was added


 * 10% Saltwater-** Started out as dark, defined circles. Then slowly dissolved into one massive grey blob

__Substance C:__ **Distilled water-** tiny and not defined, couldn't make out what it was.


 * .9% Saltwater-** Diamond shape, and are smaller than the .10 diagram. not as defined.


 * 10% Saltwater-** Bigger and more defined. Takes the shape of miniature rocks.