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This is why Daphnia is often used in experiments dealing with heart rate. Daphnia inhibits regions Of fresh water. They will not survive very long in distilled water or tap water. The reason why they would not survive long in tap water is the amount of chlorine. The amount of chlorine is so high that it would eventually kill the Daphnia. If tap water were ever to be used to host a Daphnia it would have to sit for a period of at least 24 hours in order for the chlorine amount to decrease and therefore become habitable for the Daphnia. 3 For many years people have used salt during blizzards to uncover rode’s for afar driving.
What some may not know is the impact road salt can have on the environment and the organisms that live in it. “Road salts can have affects on organisms who inhibit wetlands as far as 550 feet from the roads. “this is due to the many chemicals as well as dye that road salt contain. Both of these factors impact living things that range from trees to amphibians. When the road salt reaches high enough concentration it becomes highly acidic. As the road salt reaches the grass and soil, the salt is absorbed by the soil and affects many organisms. “In contrast to their tolerance of low oxygen,
Daphnia are very sensitive to disturbances of the ionic composition of their environment. “5 When Daphnia are exposed to salt after a certain period of time they stop moving and eventually die from these conditions. “Many variables can play in the heart rate of Daphnia as mentioned before. They are extremely sensitive to metal ions like copper and zinc, pesticides, detergents, bleaches and other dissolved toxins. For this reason, they are Often used to test waste-water from industry. ” 6 Although a lot of human products are tested on Daphnia and have affected their heart rate, one cannot assume it ill also affect the heart rate of a human.
This is because they are two different organisms and have much differences both in the anatomy and the way factors affect the conditions of each organism. Introduction In this lab you will determine the major impacts that road salts can have on the environment and the organisms that live within it. Many of the materials we use in our society harm living organisms and we are not even aware of it. These materials harm organisms because organisms are not adapted to human made materials and are not present in their natural environment.
In order to recognize how these materials affect organisms we will analyze the heart rate of Daphnia when exposed to these conditions at different concentrations in contrast to their heart rate during normal conditions. Hypothesis If the Daphnia is exposed to road salts with higher concentrations then its heart rate will be higher than that of a regular water environment. This is because road salts contain several chemicals as well as dyes that are very harmful to organisms, especially in high concentrations.
Also these organisms natural habitats do not contain these chemicals and so their systems have efferent reactions to them. My null hypothesis is the more NCAA concentration the less heart beats the daphnia will produce per minute. Variables In this lab the independent variable consist of 10 drops of road salt solutions at a concentration of 5%. This is because the concentrated solutions with road salts will be controlled to see the affect they have on the heart rate of the Daphnia. The Dependent variable will be the number or heart beats the Daphnia produces per minute.
This is because this will not be controlled since the number of beats per minute will be produced by the organism. The matron variable will be fresh water, this is to ensure what the average heart rate of the Daphnia in its regular environment. Materials 3 Petri dishes Tablespoon Filter paper Road salt Electric balance 100 ml beaker Stirring rod Microscope 100 ml cylinder (xx) Thermometer Microscope slide Fresh water Mortar & eavesdropper (xx) Timer Daphnia Proceed re Begin by obtaining 4 Petri dishes (they should all be labeled with the different solutions and their given concentrations).
Then begin to make your 5% NCAA solution. Begin by pouring one tablespoon of road salt into a mortar and crush it using a pestle. Make sure it is almost sand-like)Then put a filter paper on the electric balance and measure out So of NCAA Once you have the g of NCAA pour them into a beaker of 100 ml of freshwater. (Make sure the freshwater is at 20″ Celsius) Stir the mixture until it is homogeneous. Then add 30 ml of freshwater into the Petri dish labeled 5%NCAA solution. Then using a dropper put 10 drops of the solution into the Petri dish and stir. Set the habitat aside.
Using a different Petri dish pour 30 ml of freshwater . (Make sure the freshwater is at 200 Celsius) Then place one Daphnia into the biota. After 30 seconds transfer the daphnia with a dropper to the microscope slide and count the heart beat for 20 seconds then multiply times the number times 3 in order to have the number of beats per minute. (remember to distinguish the dropper your using in salt water and the one you’re using in fresh water) (It is very important to TURN OFF the light of the microscope when unused so high temperatures don’t alter the heart rate of the Daphnia. One you have counted the beats per minute transfer the Daphnia back to the fresh water habitat and allow the organisms to sit for 30 seconds and repeat the process. Follow this process 5 time with the same Daphnia. Once you are done with the 5 trials using a different dropper transfer the same Daphnia into the Petri dish with the 10 drops of the 5% NCAA solution. The repeat the same process you did with the freshwater. Repeat the process for the remaining 4 Daphnia then compare results.