Wednesday, March 5, 2008

Potato Osmosis

SWBAT: Perform an experiment that answers the question:
How does salt water affect potato cells?

MATERIALS: For each 8 groups:

2 slices of potato
2 cups/containers
salt water solution
tap water
paper towel
sheet of drawing paper.

OPENING: Ask students to state their hypothesis: “If we place one slice of potato in salt water and one slice in tap water, then the potato slice in salt water will (shrink) (swell) (stay the same). I think this way because……

Demonstrate the following procedure. Ask students to take notes.

Trace one of the potatoes onto the sheet. Place the slice into salt water. Do the same for the tap water. Wait for at least 30 min. Take the potatoes out of the water and dry them. Trace the potatoes again. Compare the second drawings to the first.

GROUP WORK

Follow the directions that the teacher demonstrated.

SHARE
Draw conclusion.
Apply the concept of osmosis to cells.


Homework: Write Lab Report