Introduction The purpose of this lab was to determine the normal heart rate of a Daphnia Magna and decipher the different effects that various substances had on it. A Daphnia Magna is a species of water fleas and can be located in the Northern United Sates against the coastline of the Atlantic in rocky pools. The water flea’s habitat consists of rivers and streams, temporary pools, lakes and ponds, and brackish water. The Daphnia Magna range from two to five millimeters in length and are shaped like a kidney bean (Elenbaas, Molly). Relating to this lab experiment we learned in class that the normal heart rate is measured anywhere between 60 and 100 beats per minute (BPM). If your resting BPM is measured at a level above the number 100 it is known as Tachycardia. This term indicates that your heart level has exceeded the normal range. Also if your heart rate is indicated below 60 then it is called Bradycardia, which means the heart is beating slower than normal. When your heart rate is affected by a substance in the body it is called a Chronotropic agent. When the heart rate decreases because of a substance or chemical it is called a negative Chronotropic and when it is affected oppositely by increasing it is known as a positive Chronotropic agent. In this experiment we added many different substances to the slide on which the water flea was placed to calculate the increase or decrease in its heart rate due to the ingredients in the substances. The first substance used was
Table 5. The effects of Atropine measured by the ventricle of the frog’s heart by amplitude, period, and BPMs.
In Exercise 1, diaminofluorene is used to determine the hemoglobin concentration in the daphnids. A higher hemoglobin concentration is indicated by a darker blue color. A spectrophotometer was used to determine the absorbance at 610nm. When measuring the absorbance levels a blank is necessary to have a zero reference, the blank is the “starting point” for the measurements of the sample (re-word). The blank consists of 10µL of diaminofluorene(DAF), 50µL of hydrogen peroxide, and 0.5mL of PBS. The PBS acts as a buffer in this experiment. The cuvette with the sample of daphnids consisted of 10µL of DAF, 50µL of hydrogen peroxide, and 0.5mL of the sample of Daphnia. In Exercise 2, the Pasteur pipette was used to obtain the sample of Daphnia. The depression slide used in this experiment isolated the daphnid, cotton was used to keep the daphnid still while the heartbeat was counted. The ocular micrometer on the microscope allows the tail spine length to be measured accurately, as well as using an ocular magnification table.
After completing the experiment we found that when we gave the Daphnia caffeine the heartbeat rate did show an increase. However, we also found that alcohol also increased the number of times the heart beat. Even though we performed all of the experiments very carefully, we cannot be certain that the effect we saw was due to the drugs. Perhaps the change in heartbeat rate is caused by
The dependent variable is pulsation rates of L. variegatus before and after they were in the treatments. The standardized variable of this experiment would be the temperature of the surroundings of the L. variegatus, the three pulsation rates taken for each worm before and after the treatments, and also the amount of time each worm was kept in their respective treatments. The level of treatment for this experiment would be ten because of the six different concentration treatments of caffeine and nicotine along with the four household drugs. The sample size of the experiment differed from some treatments to other. For the three different concentrations of caffeine and nicotine, the sample size was 18 black worms each. The sample size of the control treatment of week 1 was 6 black worms. 12 black worms were used for the control of week 2, decaffeinated coffee and instant coffee. 11 black worms were used for the tea treatment and 15 were used for the tobacco treatment. There were three replications of the pulsation rate readings per worm before and after the treatment. With all this information we were able to get the results we got.
The physiological effect of different medicines is successfully determined by counting the heart rate of Daphnia through this experiment. The data shows that different chemicals affect the heart rate of Daphnia differently. In the presence of Ephedrine, the heart rate of Daphnia has increased, and in the presence of Ethyl Alcohol and caffeine, the heart rate has decreased. The Daphnia under water is a control group, and the average heart rate is 269 BPM. The heart rate has decreased to 267.33 BPM when 0.5M Ethyl Alcohol is added and to 256 BPM when 0.5M caffeine is added.
5. Establish the resting heart rate of the Daphnia. Count the amount of beats for ten seconds then multiply that number by six to convert it to beats/min.
The lab handout provided by the instructor was used as a guideline to conduct this experiment. The only difference was the organism used and data collection period. For this experiment, pill bugs and crickets were utilized. Also, data was collected for a period of 12 minutes.
The following was the procedure used by the team that introduced chemicals into the environment of the Daphnia. First a zero reading was taken before any chemicals were introduced. The zero reading was an observation of the Daphnia’s heart rate before any substances were administered. All fluids were drawn off the slide using the corner of a Kimwipe. Then two drops of two percent alcohol solution were dropped onto the Daphnia. After a minute a heart rate reading was taken. The same procedure, including using the Kimwipe to draw off previous solution, was then used with four, six, eight, and ten percent solutions. A heart rate reading was taken after each solution was introduced.
The intention of the experiment was to measure how different pH levels affect the heart rate of daphnia. The objective of this experiment was to measure the heart rate of
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.
The heart serves an important purpose within the body, pumping blood throughout the circulatory system to supply all parts of the body with vital nutrients and molecules. It pumps oxygen and nutrient rich blood to be exchanged for carbon dioxide, which is then pumped to the lungs and eliminated from the body. The movement of blood throughout the body is due to the heart’s ability to push blood along the circulatory system at a steady, unfaltering rate. This rate, known as heart rate, is regulated and can be altered at a moment’s notice by signaling within the body and heart itself. In vertebrates, the autonomic nervous system controls and regulates heart rate. The autonomic nervous system is divided into two subunits, the sympathetic nervous system and parasympathetic nervous system. The parasympathetic nerve that innervates the heart is the vagus nerve. In this laboratory experiment, the regulation of heart rate was observed by studying a certain breed of turtle, the Red-eared Slider (Trachemys scripta elegans). Both chemical and electric signaling can influence the components of the nervous
The respiration rate for the control goldfish ranged from 123 to 140 breaths per minute, which was not a significant change. On average, the cold-water treatments caused a significant decrease in breaths per minute by the end of the experiment. The average the breathing rates of goldfish subjected to temperatures less than 22°C decreased from a rate of 96 breaths per minute at the start of the experiment, to 56 breaths per minute at the end (Figure 1). The experimental fish in Group #1 ranged from 115 to 50 breaths per minute. Overall, the control fish’s breath rates generally remained constant, and the temperature-stressed goldfish had rates that decreased rapidly from start to finish.
In this experiment, we tested three different conditions in the dive response to see whether heart rate decreased with each treatment. To characterize the dive response, we measured subjects’ heart rates at rest and with their face submerged under a tub full of room
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.
Now that the experiment has been tested, the results are in there comes the analysis part of the process. After I had determined my calculation I saw where my beats per minute were over a hundred; this consider me to be Tachycardia. Tachycardia refers to an abnormally fast resting heart rate. When examining what Tachycardia was and how it can be affected made me see that different scenarios will affect the beats per minute. Anxiety, caffeine, stress can all cause someone to have such a rapid heartbeat. I remember from when taking the echocardiogram that I was stressed