Daphnia are ectotherms and their body temperature changes with the surrounding environment. The small heart of Daphnia is easily visible under the low power of a microscope. The heart rate (# of heart beats) can be observed and counted when influenced by different environmental conditions. Students will be testing the effect of temperature on the heart rate of Daphnia.
Purpose of the Lab:
- To observe the beating heart in Daphnia magna.
- To determine the effect of temperature on the heart rate of Daphnia magna.
- To design an experiment to test the effect of different chemicals on Daphnia heart rate.
This resource actually contains three different activities:
- First, students will follow the enclosed lab procedure to determine how temperature affects the heart rate of Daphnia.
- Second, students will design their own experiment to test the effects of two chemicals on the heart rate of Daphnia.
- Third, students will complete the Q10 Temperature Coefficient Worksheet.
What is included in this resource?
- lab handouts that are ready to be printed and passed out to your students.
- Complete instructions.
- Diagram for each lab station to help students locate beating heart.
- Student-designed experiment handouts. (4 pages)
- Q10 Temperature Coefficient Worksheet (2 pages)
- 5-page Teacher Guide containing set-up instructions, tips, tricks, and suggestions.
- Complete Answer Key containing sample data, sample graph, and all answers.
- Everything you need for the successful completion of this lab.
Materials Needed for this lab:
- Culture of Daphnia magna
- Plastic dropping pipets
- 2 Depression slides
- Small Petri dish (bottom only)
- Cotton ball
- Warm water bath
- Graph paper
- Rubber bands
What will the students be doing?
- Using depression slides, students will assemble a simple habitat chamber for the Daphnia while it is being viewed under the microscope.
- Students will locate and observe the beating heart to determine the heart rate.
- While treating the Daphnia with care, students will observe the effects of a slightly cold temperature and a slightly warm temperature on the heart rate of Daphnia.
- Students will graph their data and complete analysis questions.
- As the instructor, you can end the lab at this point. Or, you can use the additional worksheets to have students design their own experiment to test the effect of chemicals on the heart rate of Daphnia.
- Finally, you may choose to have the students complete the Q10 Temperature Coefficient Worksheets.
This lab is a favorite of mine and is always a big hit with my students! Students love to look at living organisms under the microscope. Daphnia is particularly fun because a rapidly beating heart is clearly visible.
This product comes with three separate activities:
- All students in grades 9 - 12 can enjoy the first activity. Students will test the effect of temperature on the heart rate of Daphnia. This experiment is easy to set up. This part of the lab is easily completed by upper middle school students, and high school students.
- In the second activity, students are asked to design their own experiment to test a new variable. For students in grades 9-12, this is a MUST! Common Core standards require high school science students to fully understand and be able to carry out the scientific method by designing and implementing their own experiment. Middle school students can enjoy and complete this activity if they have been properly instructed before hand on how to design an experiment.
- The third activity is a Q10 temperature coefficient worksheet. Honors level or AP biology students should complete this worksheet.
A listing for just the Q10 Temperature Coefficient Worksheet can be found by clicking this link.
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