Daphnia Experiment Report

According to the results, the columns of caffeine in figure 1, of this experiment the hypothesis for caffeine is partially accepted. There is an increasing trend in the change of pulsation rates with increasing

Next we removed the excess solution from the Daphnia and flushed it with aquarium water. Using the same procedure we monitored the effects of 1 1/2% and 2.0% caffeine

After the Daphnia was given time to calm down, the team took a reading of its heart rate at room temperature (27 degrees C). The reading was taken by counting the heart beats for ten seconds and then multiplying by six to yield beats per minute. Next, a glass Petri dish was filled with ice water at five degrees Celsius. The cold water Petri dish was placed on the stage of the microscope, and the Daphnia was placed on top of the dish. When the Daphnia had been given a minute to acclimate to the changes, another heart rate reading was taken. Then the same procedure using the Petri dish to changed environmental conditions was used with cold tap water (23 degrees), warm tap water (30 degrees), and hot tap water (45 degrees). A heart rate reading was taken for each temperature.

The aim of this experiment was to determine the effect of caffeine on resting body temperature. This has to do with homeostasis, which is the maintenance of equilibrium. In other words, it is a stable body state. Homeostasis refers to the process of keeping the internal body environment in a steady state, when the external environment is changed (Homeostasis 2). Humans are warm-blooded creatures that generate body heat internally and maintain body temperatures at a fairly constant level – about 98.6oF (Chiras 3). In this experiment, the effect of different amounts of caffeine on resting body temperature was examined.

Central Idea: Caffeine can be found in many places and comes in many forms. It can major effects on our body and we can experience major withdrawal symptoms.

Thesis: Caffeine can have many different effects on the body depending on the amount of consumption.

In this experiment we find how caffeine can affect the heart rate of a culture Daphnia. Heart rate of a living organism’s can vary depending on the individual, age, body size, heart conditions, medication use and even temperature. This report will examine if the caffeine is good or bad for the living organism’s health and body. And discuss about where the caffeine is produced and used in daily life of human beings and on the environment. Daphnia is a water flea used in this experiment because of its genomic infrastructure with wide range of phenotypic diversity. This quality of Daphnia makes them a versatile model for the experiment. Also their transparent body allows the experimenter to visually see how the heart beats and count them under the light microscope during the experiment as required. The heart rate of Daphnia is monitored under different concentration of caffeine solution and the results are shown in a table and a graph. Experiment carried out to locate the effects of caffeine on a heart rate of Daphnia may or may not be a predictor of change in human heart rate under caffeine. The effects of caffeine can also be tested on humans but those experiment involving humans contains high risk, as Daphnia can only live for a short period of time and in nature most of them get eaten within their first few days or weeks of life.

My hypothesis was, as the concentration of alcohol increases the lower the heartbeat of the Daphnia will fall. To test my prediction I carried out 25 individual experiments which were all carried out using the same procedure but varying the alcohol concentration of the solution. To investigate how alcohol concentration affects the heartbeat of Daphnia I recorded the heartbeat of 25 Daphnia for a period of 7 minutes. This included 1 minute before submersion in alcohol, 3 minutes during submersion in alcohol and 3 minutes after submersion in alcohol. I then found the percentage decrease of the heartbeat of the Daphnia from the resting heart rate.

This paper explores and explains the findings of the heart rate experiment conducted by the students of Grand Canyon University for the Anatomy and Physiology 202 Laboratory course. Over a two week time span, students were asked to record their heart rate, before, during, and after activities as instructed by the professor. Specifically, this paper focuses on the female students, comparing the heart rates of individuals who reported that they drink coffee versus those females who reported that they do not drink coffee. The effects of caffeine contained in the coffee were examined and it was noted that those who drink coffee have lower heart rates before, during, and after times of examination. These findings suggested that the hypothesis proposed prior to research, Females Who Drink Coffee Have a Higher Heart Rate Prior to Exams, was an incorrect statement.

My hypothesis was supported in the experiment due to the fact that caffeine raised the beats per minute, while kava drastically decreased the amount of heart beats in a given minute. By looking at figure 1 you are able to see that kava decreased the heart rate by -46 beats per minute, while the caffeine raised the beats to 26 per minute. This supports the conclusion that the stimulation humans receive off of caffeine has a similar effect in Daphnia Magna. Caffeine raises the beats per minute in each individual, while kava decreases the amount of beats. This is due to kava’s relaxation properties found within it’s roots commonly called kavalactones. I assumed that the effects of caffeine and kava on humans would be similar to those of Daphnia

Experiment one tested the concentration of experimental beta blockers, and its relationship with the percent decrease in of the heart rate of the Daphnia. Our goal, was to prove that, an increased concentration of beta blockers would decrease the overall heart rate of the Daphnia being tested. Our results, established, that as the beta blocker concentration increased, so did the decrease in the heart rate of the Daphnia. Experiment two tested two unknown concentrations (A and D) and its effect on the Daphnia to see if it contained any concentration of beta blockers. The results, for concentration A showed very little effect, and concentration D seemed to have no effect on the Daphnia at all. Experiment one shows, that

Various studies have been conducted in attempts to connect the use of caffeine with increased endurance levels. Graham and Spriet (1995) conducted a double-blind test involving eight endurance runners. Each participated in a control test previous to the study in which they ran a prescribed distance, to the point of exhaustion. All ate similar meals and abstained for caffeinated substances previous to the trials. Over a four-week period, each runner returned to the laboratory to run the prescribed distance while intravenously being given varying doses of caffeine. A blood and oxygen sample was collected every fifteen minutes during the run in order to record the time span until physical exhaustion was reached. The results confirmed that low doses of caffeine caused a drastic increase in endurance levels, while not altering the epinephrine (or adrenaline) levels. Also, large doses of caffeine caused great increases in plasma epinephrine levels while only slightly altering the endurance levels. This test, therefore, supposes that small doses of caffeine, when compared to

This experiment is being performed to show the effect of pH levels on daphnia by changing pH levels and measuring the heart rate.

Base on the results, nicotine and caffeine instead of increasing the heart frequency which is the beats per minutes, they actually did the opposite, they decrease the frequency of the heart and in some cases the amplitude. If we look at table 1 and compare the figures , were 2 drops of caffeine were add, the data shows no effects is done by caffeine, no increase or decrease in heart rate. The same problem happen when 10 drops of caffeine were added to the heart, there was no sign of a big change for the frequency, it only have a change from 59 to 60 BPM if we compare resting and 50 secs after caffeine was added. The only time where there is a difference was at the second trial of 2 drops of caffeine. The frequency drops from 57 to 47 BPM after

7. The relation between palpitations and energy drinks could not be proven. ECGs were not able to prove QT prolongation and only a few subjects demonstrated ventricular abnormalities.