All Science Fair Projects

Over 1000 FREE Science Fair Project Ideas!

Green tea and DaphniaFeatured science projectScience project video


The materials required for this science fair project:
- 160 daphnia
- 7 beakers
- A packet of green tea powder
- A tablet of Altace
- A microscope
- 7 glass slides
- 1 digital weighing scale
- 1 stopwatch
- 700ml distilled water
- 1 measurement cylinder
- 1 eyedropper
- An assistant


1. For this science project, the independent variable is the concentration of  green tea and Altace solution. The dependent variable is the heart rate of the daphnia. This is determined by counting the heart beats per minute while viewing the daphnia under a microscope. The constants (control variables) are the room temperature, amount of water used and the concentration of the solutions.

2. The first beaker is labeled "water" and filled with 100ml water. The remaining 6 beakers are labeled and prepared as explained in the table below.



100ml water with 0.1gram tea


100ml water with 0.1gram Altace


100ml water with 1.0gram tea


100ml water with 1.0gram Altace


100ml water with 10gram tea


100ml water with 10gram Altace

4. The daphnia are separated onto the 8 slides with 20 daphnia specimens on each of the slides.

5. 3 drops of water  are  added on the 1st slide and then viewed under a microscope. The number of heartbeats per minute is counted for each daphnia while the assistant monitors the time with the stopwatch. The average heart beat per minute of the daphnia is calculated by totaling all the heartbeats and dividing by 20. The result is recorded in the table given below.

6. On the next slide, 3 drops of solution from the beaker labeled Tea0.1  are added. After 15 minutes the slide is placed under the microscope and the heartbeat of the daphnia are again counted as explained in procedure 4. The result is recorded in the table given below.

7. Procedure 3 is repeated using 3 drops of solution from the beakers labeled Tea1.0, Tea10, Altace 0.1, Altace1.0 and Altace10 and placing them on different slides. The heartbeat is counted and the results are recorded in the table.

See our all-time most popular science projects
Search science fair projects Browse science fair projects
popular science fair projects
Complexity level:
Project cost ($):
Time required:
1 hour to prepare, 1 day for science fair project
Material availability:
Easily found
Safety concerns: