Water-Flea

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Science Simulations, Technology Simulations, Engineering Simulations, Mathematics Simulations

Lesson 6: Which Drug Causes the Largest Heart Rate Change?

Water fleas are small aquatic organisms that make up one part of plankton. They can be used to test the effect of various drugs on their heart rate. In this investigation, you’ll determine which drug causes the largest change in the organism’s physiology. Check your pulse and get started in this study of drug effects.

Doing the science

Start the Water Flea Simulation by clicking on the “Simulation” tab.
You can use the Timer Counter on the left side of the screen to find the water flea’s heart rate or you can use a stopwatch.
To use the Timer Counter, click the “Start” button, then click the “Click Me” button each time the flea’s heart beats.
After getting in the rhythm of the beats, click the “Stop” button and the flea’s heart rate will be displayed in beats per minute in the space below the buttons.
Record this value (normal heart rate) in Table 1.
Select the “Alcohol” button, then select the “Double Dose” button. Count and record in Table 1 the flea’s new heart rate.
Select the “Clear” button.
Select the “Sleeping Pills” button, then select the “Double Dose” button. Count and record in Table 1 the flea’s new heart rate.
Select the “Clear” button.
Select the “Caffeine” button, then select the “Double Dose” button. Count and record in Table 1 the flea’s new heart rate.
Select the “Clear” button.
Select the “Nicotine” button, then select the “Double Dose” button. Count and record in Table 1 the flea’s new heart rate.
Select the “Clear” button.
Select a Male water flea and repeat steps 3 – 13. Make sure to record your data in Table 1.

Calculating

Calculate and record in Table 1 the change in heart rate of the flea after taking the drug by subtracting the heart rate after taking the drug from the normal heart rate. Please note that some of these values will be negative numbers.
Calculate and record in Table 1 the Percent Change of the heart rate. Do this by dividing the change in heart rate by the normal heart rate, and then multiplying this value by 100 to convert the value to a percentage.

Do You Understand?

Which drug had the largest effect on a female water flea’s heart rate?

Which drug had the largest effect on the male’s heart rate?

Which drug had the smallest effect on a female water flea’s heart rate?

Which drug had the smallest effect on the male’s heart rate?

Which of the tested drugs should be classified as stimulants?

Which of the tested drugs should be classified as depressants?

Antagonistic effects arise when a person is exposed to multiple substances and as a result the person’s response is less than what is expected if the two substances’ effects were added together. Which combination of two drugs in this study might result in an antagonistic effect?

Synergistic effects happen when the effect of two or more substances added together is much greater than simply adding the effects of the two things taken individually. Which combination of two drugs in this study might result in a synergistic effect?