## MaterialsThe materials required for this science project: ## Procedure1. For this experiment, the independent variable is the concentration of Red Bull solution used. The dependent variable is the number of heartbeats per minute of the daphnia. This is determined by viewing the Daphnia under a microscope and counting the number of heartbeats. The constants (control variables) are the room temperature, the amount of water used and the concentration of the solutions. 3. The daphnia are separated into 4 groups of 10 Daphnia each. Each group of 10 Daphnia is then placed on the 4 slides. 4. The testing is started by placing 3 drops of water on the 1 ^{st} slide. Wait 15 minutes and then place the slide on the microscope. The number of heartbeats for each of the 10 Daphnia in the slide is counted one at a time while the assistant keeps time. The heartbeats per minute for the 10 Daphnia are totaled and divided by 10 to obtain the average heartbeat. The results are recorded in the table given below.5. On the remaining 3 slides, 3 drops of the solution marked Red Bull 0.1, Red Bull 0.5 and Red Bull 1.0 are added to each slide. The number of heartbeats for each Daphnia is counted as explained in procedure 4. The average heartbeat is calculated and recorded in the table given below. |