Daphnia Magna Lab Report

Aim: The aim of this experiment is to understand the affect of the drug Caffeine on the rate of a Daphnia’s heartbeat. This is to understand the affect of caffeine on a human’s heart rate and the use of daphnia keeps the experiment fair and safe.

​The data shows that when the temperature of the water surrounding the deep well slide containing the Daphnia magna increased, the heart rate of the Daphnia magna increased, and when the temperature of the water decreased, the heat rate of the Daphnia magna decreased as well. For example, when the water was at room temperature, 21° C, the average heart rate was 393.33 BPM. When the water temperature was increased to 30°C, the average heart rate increased to 510.66 BPM. When the water temperature was decreased to 10° C, the average heart rate in beats per minute decreased to 332 BPM, less than both the 21° C and 30° C results. The warmer the water temperature was, the higher the heart rate of the Daphnia magna.

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

← As for the daphnia, there is a chance for them to die as when they are exposed to light, they are also exposed to heat in which they aren’t used to.

effected the heartbeat rate of a Daphnia. The results of the experiment were that the

Heart rate of daphnia fell from an average of 274.455+/-26 beats per minutes to an average 246.868+/-71 heart beats per minute. After performing Mann-Whitney U statistical test, this difference in heart rate was found to be statistically not significant.

Ectothermic animals are animals whose body temperature is affected by their surroundings. This means that if the environment is cold the animal will be cold. If the environment is warm the animal will be warm. This is because the animal doesn’t have the capability of regulating its body systems to keep a constant body temperature. When an ectothermic animal is cold, its heart rate will lower. When the animal is warmer, the heart rate will raise – as long as the temperature isn’t sufficiently high to harm the animal. (Campbell, 2005)

vulgaris plants, via the formation of a standard curve prepared using varying concentrations of bovine serum albumin (BSA) solution. Following absorbance readings of the various BSA solutions, they were plotted against their concentrations providing an indirect measure for determining protein concentrations of the plant samples within the assay tubes, and through further calculations the sample protein concentration. The mean protein concentration for the control group was calculated to be 3.34 ± 1.30 mg/mL, while the mean treated group concentration was 2.01 ± 1.26 mg/mL. These results similarly like the chlorophyll results correlate with the literature articles, as a reduced protein content within the Paraquat treated plants can be expected to some extent (Chia et al., 1981). This reduction in protein concentration is the result of those superoxide anions produced by Paraquat, disrupting the chloroplast membranes and allowing for intracellular components including some proteins to leak out, hence the decrease in protein concentration in comparison to the non-treated plants (Qian et al., 2009). A slight outlier may exist within the treated groups protein concentrations as one of the groups provided a negative value for protein concentration which is not valid, but even after exclusion of that data value, results are still supportive of the expected outcome. Though these results support the claim of Paraquat toxicity causing membrane deterioration and leakiness, protein concentration values are rather more purposeful when used to analyze malondialdehyde (MDA) values on per mg of protein

This laboratory exercise was performed to visualize the effects of various drugs on the heart rate of Daphnia magna. The four drugs tested consisted of: Lidocaine, Acetylcholine, Caffeine, and Nicotine. These drugs were designed to have an apparent effect on the average heart rate of the Daphnia. The laboratory exercise was divided into two parts and procedures: measuring the basal heart rate of Daphnia, and measuring the drug induced heart rate of Daphnia. In order to measure the basal heart rate, various Daphnia were obtained and observed under a microscope at 40x magnification for two separate trials. Using the same technique, the drug induced heart rate with each drug (Lidocaine, Acetylcholine, Caffeine and Nicotine) was measured and

Common testing conducted by researchers uses many features of Daphnia. The transparency of Daphnia and the visibility of their hearts is the basis for the majority of experiments conducted on Daphnia. (Villegas-Navarro, Roses-L & Reyes, 2003). Many other researchers have conducted experiments on Daphnia while also paying attention to the cardiovascular region of Daphnia (Campbell & Matthews, 2004). Researchers have

The experiment goal was to measure the effects that different water temperatures had on the Daphnia's heart rate and the effects of epinephrine as well. Daphnia is commonly known as water flea bugs that are small aquatic crustaceans that is found plentifully in small bodies of fresh water (General Biology Study Guide and Lab Manual, 10th ed. 2007). These water bugs are good animals to use for this type of experiments because they are large enough to be seen without a microscope in light and under the microscope at twenty times magnification their internal organs can be seen straight through their body cavity. Daphnia are ectothermic creatures, meaning

The purpose of this experiment was to test the affect of caffeine on the heart rate of Daphnia by observing their behavior and heart rate under a microscope when exposed to different concentrations of caffeine. Caffeine is a stimulant drug used in many energy drinks and causes large amounts of stimulatory neurotransmitters to be released. Therefore, as caffeine is a stimulant drug it was hypothesized that the Daphnia heart rate would increase immensely. Daphnia is a group of microscopic, planktonic crustaceans that are arthropods that measure 1-5 millimeters in length. Daphnia live in multiple aquatic environments such as freshwater lakes, ponds and rivers. “The development of genomic infrastructure coupled with a wide range of phenotypic diversity make Daphnia a versatile model

Remember to use an efficient counting method and count the Daphnia’s heart rate for 15 seconds, multiply all your trials by four to get the beats per minute. Do no less than five trials to be accurate. Keep in mind that you need to test the Daphnia’s heart rate in its regular habitat before performing the

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.

The experiment took place in a laboratory setting, and the first step was obtaining sixty individual Daphnia magna (that were neither adults nor tiny offspring) from a large tank in the lab. These individuals were equally divided into three groups; low density, medium density, and high density. The twenty Daphnia assigned to the low density group were split into four groups of five and pipetted into one of four tubes filled with 10mL of Chlamydomonas algae. The twenty Daphnia assigned to the medium density group were split into two groups of ten and placed into one of two tubes also filled up to 10mL with Chlamydomonas. The final twenty Daphnia were all placed into a single tube filled with 10mL of the algae. In order to avoid suffocation-related