The effects of different concentration levels of ammonium sulfate in daphnia magna
Introduction
LD stands for Lethal Dose and the 50 indicates 50 percent or easier understood as the lowest dose at which a material kills half of the test subjects. This value gives you an idea of the relative toxicity of the material given in milligrams of compound per kilograms of body weight. When running a toxicity test it’s important to understand how the toxic substance affects the physiological function of individuals and how this toxin affects the demography (birth and death rates) of the population. The effect of the toxic substance may also vary among populations of a species as well as among species. Since different chemicals cause different toxic effects, different toxicity tests are required depending on how the chemical will be used. The LC50 value should be used as an aid in developing emergency procedures in case of a major spill or accident, to come up with appropriate safety clothing and equipment, and to develop transportation regulations.
For this lab the aquatic organisms, Daphnia Magna, are used as indicators. These creatures are freshwater crustaceans commonly used when checking the conditions of water (lake, river, and stream). The fact that Daphnia are very sensitive to changes in chemical composition of water, here they were used to find the LC50 of different concentrations of ammonium sulfate. The whole point of the lab is to wind up with the toxicity levels of different solutions determined by the use of Daphnia.
Methods and Materials
Using a graduated cylinder, 70 mL of spring water was poured into five cups labeled 0.00%, 0.02%, 0.03%, 0.04%, and 0.05%. The 0.00% was left as the control variable with spring water only while the others had ammonium sulfate measured and added according to their concentration levels. With the use of pipets, 5 Daphnia were carefully drawn up and released into each cup, with rarely any culture water so it wouldn’t dilute the solution and affect the results of the toxicity test. The station was cleaned up and had the five cups placed somewhere safe for 24 hours. The next day, the 25 Daphnia were observed to determine the numbers that were still alive in each cup. During this lab, what’s being controlled is the concentration of ammonium sulfate therefore known as the independent variable. The dependent variable here is the number of dead Daphnia.
LD stands for Lethal Dose and the 50 indicates 50 percent or easier understood as the lowest dose at which a material kills half of the test subjects. This value gives you an idea of the relative toxicity of the material given in milligrams of compound per kilograms of body weight. When running a toxicity test it’s important to understand how the toxic substance affects the physiological function of individuals and how this toxin affects the demography (birth and death rates) of the population. The effect of the toxic substance may also vary among populations of a species as well as among species. Since different chemicals cause different toxic effects, different toxicity tests are required depending on how the chemical will be used. The LC50 value should be used as an aid in developing emergency procedures in case of a major spill or accident, to come up with appropriate safety clothing and equipment, and to develop transportation regulations.
For this lab the aquatic organisms, Daphnia Magna, are used as indicators. These creatures are freshwater crustaceans commonly used when checking the conditions of water (lake, river, and stream). The fact that Daphnia are very sensitive to changes in chemical composition of water, here they were used to find the LC50 of different concentrations of ammonium sulfate. The whole point of the lab is to wind up with the toxicity levels of different solutions determined by the use of Daphnia.
Methods and Materials
Using a graduated cylinder, 70 mL of spring water was poured into five cups labeled 0.00%, 0.02%, 0.03%, 0.04%, and 0.05%. The 0.00% was left as the control variable with spring water only while the others had ammonium sulfate measured and added according to their concentration levels. With the use of pipets, 5 Daphnia were carefully drawn up and released into each cup, with rarely any culture water so it wouldn’t dilute the solution and affect the results of the toxicity test. The station was cleaned up and had the five cups placed somewhere safe for 24 hours. The next day, the 25 Daphnia were observed to determine the numbers that were still alive in each cup. During this lab, what’s being controlled is the concentration of ammonium sulfate therefore known as the independent variable. The dependent variable here is the number of dead Daphnia.
Table 1. Percent mortality of Daphnia in various concentrations of ammonium sulfate after 24 hours
Concentration of Ammonium Sulfate Number of Daphnia Initially Introduced Number of Dead Daphnia After 24 Hours Mortality (%)
0.00% 5 0 0%
0.02% 5 5 100%
0.03% 5 5 100%
0.04% 5 5 100%
0.05% 5 5 100%
0.00% 5 0 0%
0.02% 5 5 100%
0.03% 5 5 100%
0.04% 5 5 100%
0.05% 5 5 100%
Results
Table 2. Class data of percent mortality of Daphnia in various concentrations of ammonium sulfate after 24 hours
Concentration of Ammonium Sulfate Number of Daphnia Initially Introduced Number of Dead Daphnia After 24 Hours Mortality (%)
0.00% 25 1 1%
0.02% 25 25 100%
0.03% 25 24 99%
0.04% 25 24 99%
0.05% 25 25 100%
Conclusion
After the exposure of Daphnia to different concentrations of ammonium sulfate the estimate LC50 is at 0.01%. This is the lowest dose at which ammonium sulfate kills half of the organisms. If this pollution occurs in a lake with Daphnia the population would decline and cause an imbalance in ecosystem. There are other organisms in there that depend on them, so if Daphnia are dead, other organisms die and affect the food web.
After the exposure of Daphnia to different concentrations of ammonium sulfate the estimate LC50 is at 0.01%. This is the lowest dose at which ammonium sulfate kills half of the organisms. If this pollution occurs in a lake with Daphnia the population would decline and cause an imbalance in ecosystem. There are other organisms in there that depend on them, so if Daphnia are dead, other organisms die and affect the food web.