Daphnia Heart Rate – Lab Report

Caffeine is a stimulant which is derived from leaves, flowers and seeds of plants. The plant uses the caffein as a way to repel insects as it is used as a natural pesticide by paralyzing and killing certain insects. It is used as a stimulant to human the central nervous system by enlarge the stimulatory of the neurotransmitters, however high levels of caffeine to the body whoremaster cause personal prepares of insomnia, stress, anxiety, weight loos or high blood pressure. In this investigation the effect of caffeine was observed on water flea figure 1 a water crustacean, usually known as a water flea, normally found in a aquatic areas like kittys, lakes, streams or rivers. They were used because this species of water fleas has a transparent exterior and it is easier to observe the perfume set up of the Daphnia by means of the microscope.VariablesIndependent variablesSame volume contrasting closeness of caffeine. Dependant variables bosom direct of Daphnia.Controlled vari ables.Time.Temperature.Size of Daphnia.MethodEquipmentCavity slip.Small piece of cotton wool.Pasteur pipette.Caffeine at different assiduitys.Microscope.Tally counter.A piece of wool is bedevil and made into a small loop.The woollen loop is fixed onto a cavity slide.A Daphnia is picked kayoed from a beaker containing the Daphnia with a pipette and then placed in to the loop on the cavity slide The Daphnia used pick out been left to refrigerate so that the purport rate has been lowered. Immediately after placing the Daphnia onto the slide add pond water was added or the first concentration of the caffeine but adding the uniform volume each eon moreover different concentration. The Daphnia was placed onto the microscope with a low lighting. Using the tally counter the heartbeat of the Daphnia is counted for 30 seconds. When finished the Daphnia was placed into a new beaker of water. When repeat a test a different Daphnia is used.PredictionThe concentration of the caffeine i n the blood of Daphnia willing determine the heart rate of the Daphnia. It will be directly proportional to each other, meaning that the increase of the concentration of the caffeine will give an increase of the heartbeat. This prediction can be justified with the fact that caffeine is a stimulant medicine that affects the central nervous system, speeding up your metabolism and increasing alertnessResultsCaffeine Heart Rate (BPM) analyse 1 Test 2 Test 3 Test Average 0 196 190 194 194 0.1 great hundred 172 140 144 0.2 120 172 140 144 0.3 272 316 278 288.6 0.5 300 306 306 300Ethical issuesAlthough there are no laws of tax shelter of Daphnia, they are still living organisms that need to be treated with reverence, memory them exposed to environments that they are not naturally acquainted with would deem unethical, so projectting them back into pond water when finished would be proper. It could be argued by animal rights or religious views that experimenting on whatever mixed bag of living is wrong as they also probably feel pain, although they may not suffer in the same way as high animals they should be correctly returned to their natural habitat after observation.Risk assessmentPreventionCaffeine Concentrations in eyeball or spillages onto clothes. Caffeine concentrations could splash into the eyes causing irritation, this could be prevented by wearing goggles. Also to prevent close being damaged by spillages a lab coat should be worn.MicroscopesHeat from the microscope can be abusive to the Daphnia, keeping the brightness low wont kill any Daphnia. Glass ware breaking. Handling any glassware for example beakers or petri dishes with care. Wearing goggles or a lab coat will help towards preventing any accidents.Source of errorBecause we had to count the heart beat ourselves it is unreliable as we werent able to click fast enough or clicked unrivalled to many when there wasnt a heart beat or fail heartbeats all together. -Each time a different concentration of caffeine was added a different volume of distilled water was also added each time. As intimately as different volumes of caffeine. -A different Daphnia was picked out every time a new test was carried out, so they may have been different age/size/gender, this can cause different results. -The timing system was not precise each time a test was carried out as the 30 seconds was either just under or just over. -Because of handling the Daphnia from the beaker to the petri dish to a light under the microscope could put the Daphnia under pressure giving them a raised heart beat any way.ConclusionOur results show a curve of 0% concentration being higher than 0.1% and 0.2% concentration, this could be because of a source of error, as the interpret shows a positive correlation of the increase of the caffeine percentage of concentration to the heartbeat of the Daphnia. The results did not fully match with the pr ediction made as the caffeine concentration % at 0.2 was less effective than 0.1, this may have been a human error, but other than that it seemed to support the prediction as the heart rate tends to increase from 0.2 onwards as there is a considerable increase from 0.2 to 0.3. Withthe sources of error affecting the results making them inaccurate, we could improve the reliableness of the test by improving the count of the heartbeat of the Daphnia or using bigger animals so that the heart is easier and quicker to find. Doing trial runs or repeating the test more times could help towards the reliability of the test.ReferencesEn.wikipedia.org. 2013. Caffeine. online forthcoming at http//en.wikipedia.org/wiki/Caffeine Accessed 15 Oct 2013.En.wikipedia.org. 2013. Daphnia. online Available at http//en.wikipedia.org/wiki/Daphnia Accessed 15 Oct 2013.