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Daphnia Heartbeat Solutions

Investigative Question: Will a Daphnia’s heart beat slow down or speed up when put into caffeine solution?

Hypothesis: I think that the Daphnia’s heart beat rate will increase if you place it into caffeine because caffeine gives helps you keep stay awake.

Drawing:


















Procedure:
Step One: Gather your materials

Step Two: Fill up two cups with water and using a large pipette, get 3 water fleas from its container and place them into one of the cups.

Step Three: Using a pipette carefully move one daphnia and put it in a cavity slide. Drop
Two drops of water on top of the daphnia.

Step Four: Place a cover slip over the flea, this is the control group.

Step Five: Place the slide onto the microscope and turn it on. Look into the microscope and count the flea’s heart beats over a 10 second interval and record.
Step Six: Drop two drops of caffeine solution on the same flea and place it back under the microscope, this is the experimental group. Count its heart beats for another 10 seconds and record.

Step Seven: Take out the cavity slide and remove the cover slip. Take the flea out of the cavity slide and place it into the cup without any fleas in it. Then return the flea back into its natural environment.

Step Eight: Repeat steps Three to Seven, three times.

Step Nine: Calculate the fleas heartbeats per/minute, graph the data, and compare the control group with the experimental group.

Variables:
In this experiment there are many things that could affect the data we obtain. We will do our best to control them. One thing we will control is the rate of heart beats from one of the daphnia...