Daphnia Hypothesis

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Introduction Daphnia are planktonic crustaceans2, more commonly known as a water flea. They are microscopic and most commonly found in ponds or lakes. These fleas have flat leaf-like legs that help them move through the water2. Male Daphnia are smaller than female but have larger antennules and their first legs have hooks that are used for clasping2. In spring and summer female Daphnia are more commonly found than male1. Female Daphnia can fertilize without male1. A male Daphnia is more common in fall and winter months while they fertilize egg for the spring1. Our objective was about understanding the scientific method, and we used the Daphnia to do this. The goal was to look at the affect caffeine and ethanol would have on a Daphnia’s heart …show more content…

With a higher percent of either, there would be a greater affect. Daphnia’s hearts are located dorsally with an open blood circulation, and have about 200 beats per minute2.
Material and Methods This research steps are found in an organismal diversity lab manual, in the chapter scientific investigation using Daphnia written by P.J. Castle and G.S. Paulson. To start the research, the the group of investigators set up the microscope that will be used to look at the specimen at room temperature around two O’clock in a lab at the Franklin Science Center at Shippensburg University. Carefully the Daphnia was placed on a depression slide that was then prepared to be used, but made sure to not kill it. Once the slide and the microscope was set up the researchers examined the organism …show more content…

The overall average of the control Daphnia’s heart rate is 249.38 bpm. 0.01% caffeine’s average is 327.93 bpm, and the caffeine at 0.005% has an average of 268.90 bpm, both making the heart rate speed up. Ethanol had the opposite affect, 0.01% ethanol’s average heart rate for this experiment is 159.58 bpm and 0.005% ethanol had an average of 183.4 bpm. Caffeine has a positive percent change while ethanol has a negative percent change in the data chart. The percent change for 0.01% caffeine is 31.50%change, for 0.005% of caffeine it is 7.83% change and for ethanol 0.01% it is 36.01% change while 0.005% ethanol has a 26.47% change. The standard deviation for the treatments all relatively close. Caffeine 0.01% had a standard deviation of 49.77, 0.005% caffeine’s standard deviation is 58.95. The standard deviation for 0.01% ethanol is 54.19, ethanol 0.005 had a standard deviation of 49.47, and the control groups is 33.31. The p-tests show if and how significant the data

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