1. THE DAILY NEWS 18 Wheeler Full of Salt Crashes into Lake Hefner
THE WORLD’S FAVOURITE NEWSPAPER
- Since 1879
18 Wheeler Full of Salt Crashes into Lake Hefner

2. This just in!
An 18 wheeler full of salt has crashed into Lake Hefner The lake is home to many freshwater plants and animals It is your job to determine what will happen to these organisms and try to come up with a way to reverse the damage

3. Elodea Lab
In order to determine what will happen to the plants and animals in Lake Hefner we will run a few tests of a fresh water plant called Elodea

4. Thinking back to the Egg Lab
What happened when we placed the egg in corn syrup? Why?

5. Elod-a Solutes!
Today you will prepare and observe Elodea cells in distilled water and salt water
You will need to draw what you observe in each scenario.

6. Predictions/Hypotheses
What do you think will happen to the elodea when we place it in salt water? Why?
What do you think will happen to the elodea when we place it in distilled water? Why?
What do you think will happen to the elodea when we place it in tap water? Why?

7. Elod-a Solutes! Pre-Lab Questions: What does homeostasis mean?
What cell part plays a major role in cell transport?
What do you expect to happen when you place a cell in a solution with a HIGH solute concentration?
What do you expect to happen when you place a cell in a solution with a LOW solute concentration?

8. Safety Microscopes and slides are fragile. Handle them carefully.
If anything breaks, inform teacher immediately

9. Analyze and Conclude
Describe the general shapes of the Elodea cells you observed in Part A.
What structures did you see in the Elodea cells? Describe the functions of each of the structures you saw.
How are plant and animal cells different in structure?
Explain your observations in step 13 in terms of osmosis.

10. Analyze and Conclude
What part of the cell is involved in the processes you observed in steps 11 and 13? Explain your answer.
What biological concepts are responsible for the changes you observed in steps 11 and 13.
Why don’t Elodea cells burst when they are in distilled water? Relate you answer to the differences between plant and animal cells.

11. What will happen to the organisms in Lake Hefner?
Lake Hefner is a reservoir for Oklahoma City’s drinking water. How will the residents of OKC be affected? C.E.R. Statement

12. Fixing the Problem
With your partner discuss ways to reverse the damage to Lake Hefner
Pair up with another group and compare ideas
Decide on a plan and be ready to share with the class