La! Crime Investigation Unit:

Where Did Tony Drown? Was it an Accident?

Test #2:

 

You will use principles of osmosis to determine if the fluid in Tony’s lung tissue contains salt water.

  1. Make a prediction about the effect of placing the lung tissue in salt water.  We predict that if Tony (circle one) DID / DID NOT drown in the ocean then after placing the lung tissue in distilled water the cells will (circle one) INCREASE / DECREASE / REMAIN UNCHANGED because ____________________________________________________________________________________________________________________________________________________________

  2. Take two samples of Tony’s lung tissue and dry it with paper towel.

  3. In Data table 2 trace each piece of Tony’s lung tissue. 

  4. Using the balance weigh 15 grams of salt into the plastic cup labeled salt water.

  5. Add 100 mL of distilled water to the plastic cup labeled salt water and stir to dissolve the salt. 

  6. Add 100 mL of distilled water to the plastic cup labeled distilled water.   

  7. Add one sample of lung tissue to the cup labeled salt water and one sample of lung tissue to the cup labeled distilled water. 

  8. Allow the lung tissue to sit in the cups a minimum of 25 minutes then remove the lung tissue, dry the tissue with a paper towel, lay the sample of tissue DIRECTLY OVER the previous tracings and using a different color pen retrace the lung tissue.  Write your conclusions on the Evidence Report Sheet.  While you wait for the tissue to process move on and complete Test #3. 

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