Biology Lab: Measuring the Heart Rate in Daphnia
Daphnia are tiny crustaceans, closely related to a shrimp. They are often called “water fleas”. Daphnia are ectotherms and their body temperature changes with the surrounding environment. This further means that there is a direct correlation or relationship between the rate of internal physiological activities and the external temperature of the 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.
1. To observe the beating heart in Daphnia magna.
2. To determine the effect of temperature on Daphnia heart rate.
3. To design an experiment to test the effect of different chemicals on Daphnia heart rate.
Materials Needed: Culture of Daphnia magna, Plastic dropping pipets, Depression Slides, Small Petri dish (bottom only), Cotton ball, Thermometer, Ice, Warm water bath, Stopwatch, Microscope, Graph paper, Rubber bands
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:
1. All students in grades 6-12 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 middle school students, and the high school students will enjoy it as well.
2. 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.
3. The third activity is a Q10 temperature coefficient worksheet. Honors level or AP biology students should complete this worksheet.
Included in this product:
1. Two versions of the basic lab. Use version 1 if you want your students to use their own paper to write their own lab reports. Version 2 contains student friendly worksheets on which students record their data and answers.
2. A 4-page handout for students to design their own experiment to test the effects of caffeine and alcohol on the heart rate of Daphnia.
3. A sample student designed experiment.
4. A 5-page Teacher Guide with teacher preparation notes and answers to all questions.
5. Q10 worksheet for Honors and AP students.
6. Images and photos
Your download will include multiple formats: docx, doc and PDF.
A listing for just the Q10 Temperature Coefficient Worksheet
can be found by clicking this link.