Daphnia: The reason Daphnia is used as the organism in this experiment is due to its transparent body which makes the heart visible. Figure 5: Trial Two Heart Rate Figures 2-5: Click on any graph to enlarge. Variables: The independent variable that we change. The safest, most hygienic and most convenient ways to provide the necessary food for a colony of Daphnia is to feed them on a few drops of a suspension of fresh yeast or of egg-yolk medium made by blending a hard-boiled egg in 500 cm 3 of water. More importantly, Daphnia are transparent, thus allowing clear visualization of different organs, including the heart.
The control for this experiment is a solution with no caffeine which allows us to see if the change in heart rate is due to the caffeine or other factors. Accuracy Certain methods of collecting data were not accurate therefore affecting the validity. Volume of solution The time heartbeat is measured within Temperature: Daphnia may be very sensitive to the heat therefore the kinetic energy given to them by heat could have effects on the heart rate. This experiment was performed two times, and a paired t test analysis vs control indicated the following P values: 0. The lab setup The purpose of the first experiment was to examine their population growth, heart rates, and reflex quality.
Kundu A, Singh G: Dopamine synergizes with caffeine to increase the heart rate of Daphnia. For the blue squares curve, at least one lower concentration should be tested. Retrieved May 2000 from the World Wide Web. In this practical the caffeine should have a noticeable effect on the heart rate of Daphnia as Daphnia absorbs chemicals present in the solution around it without selection. I also predict that there would be an increase in heart rate once placed in decaffeinated coffee as decaffeinated coffee still has caffeine content but significantly lower per milligram than caffeinated coffee. As expected, the daphnia that were exposed to the 1% concentration of caffeine had a significant increase in. They cancel each other out.
Where can the materials be found? If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. It was found that there were some direct correlations between birthrate and total chlorine, as well as between heart rate and phosphate. He led me to information about the plant and the findings from the remediation project. In this study Penalva, et al. Volume and concentration of caffeine 3.
Plants produce caffeine as an insecticide. It is most commonly consumed by humans in infusions extracted from the seed of the coffee plant and the leaves of the tea bush, as well as from various foods and drinks containing products derived from the kola nut. It helped me identify the limitations in the experiment and how to conduct the experiment appropriately. To highlight experimental and investigative assessment objectives. Hypothesis: I believe that the amount of caffeine in the blood will be directly proportional to the Daphnia's heart rate.
At Long Creek, the population level in water from the entry site was close to that in the exit-site water, but was still greater. Exposure to D2-like dopamine receptor agonists inhibits swimming in Daphnia magna. Caffeine increases the heart rate of Daphnia in a dose-dependent manner. A favourable drink is Red Bull. Air bubbles make Daphnia float at the surface, unable to swim, which will eventually kill them. It is considered ethical to use invertebrates such as daphnia rather than large organisms e. Since blood volume is proportional to body mass, this is a rough way of normalizing the dose to blood volume.
Once pollution occurs… Effects of Chemicals on Heart Rates in Organisms. This study shows that stimulants and depressant affect heart rate. It was alarming to see how much the lower food chain, represented by the Daphnia magna, was affected by water quality, even though the traditional water-testing methods showed that all the contaminants within the water were well within legal limits. Introduction: I believe the results will comply with my prediction. However, pollution contributes additional risk factors that can increase the level of destruction. High levels of caffeine have been linked to increased stress and insomnia, which is also linked to heart disease… The Effect of Various Movie Genres on Heart Rate in Teenagers Defining the Problem Recent studies have show emotions have been found to have more physical effects than previously thought. While they were under the microscope, we counted their heartbeats for twenty seconds then multiplied the number by three.
We can dilute certain chemicals and apply them to Daphnia, and watch to see if the heart rate changes! Find the average heart rate of Daphnia with a 0. Don't worry about having to learn how to take a crustacean's pulse: you can actually see the heart beating under a microscope. These experiments were part of a study, where 18 different molecules were tested for their effect on heart rate, however, only caffeine, dopamine and ethanol showed drastic changes. Water, on the other hand has the lowest variability of only 60. Caffeine is also widely known by several other chemical names which include 1,3,7-trimethylxanthine, trimethylxanthine, methyltheobromine, 7-methyltheophylline, theine, mateine, and guaranine. Also, the levels of nitrate remained steady at two of the three entry sites.