lab report about the effects of Sodium Chloride on the speed of paramecium
The Effects of Sodium Chloride (NaCl) on The Speed of Paramecium By: Carina Correa Lab Partners: Suhaima Islam, Mushtari Khanom, Charles Saldana Biology 10100 - Section February 22, 2020 Hypothesis with Justification: A paramecium is a single-celled living organism from the kingdom of Protista that can be found in freshwater. Paramecium tetraurelia obtain energy from the food they eat which is bacteria and decaying plant matter. Paramecium tetraurelia eat by using its cilia to push the food along with water down the oral groove and into the cell mouth. The surface of the cell is covered with cilia which are hair-like appendages that help them move. The principal movement of a Paramecium tetraurelia is that when it encounters a negative stimulant it turns and proceeds going forward until another stimulant is encountered. The Paramecium can also avoid any strong chemical by turning around in the opposite direction to locate an escape route. The cilia that are around the oral groove moves more intensely than the rest and so the Paramecium does not swim in a perfect line. The angled movement of its cilia causes the paramecium to rotate. For this experiment, our goal was to observe the change in speed per second of the Paramecium tetraurelia when adding a chemical compound into their environment. Before the experiment, individual lab groups conducted separate preliminary experiments to test the swimming speed of Paramecium in many different solutions. Some groups hypothesized that that solution would decrease the swimming speed of Paramecium and others that it would increase. During our class presentations, each group presented their experimental results and concluded whether the speed would increase or decrease based on these results. Sodium Chloride is known as salt and can be used to regulate the amount of water in a person's body. Sodium Chloride is also “the most commonly used ice melter.”[footnoteRef:0] When Sodium Chloride is used on streets all of the melted liquid ends up in large bodies of water where Paramecium can be found. Therefore, we wanted to observe what kind of effect the addition of Sodium Chloride would have on the environment of the Paramecium. The presentations and prior knowledge led to the following hypothesis: If we add 25mL of Sodium Chloride (NaCl) then the speed of the Paramecium will decrease. [0: https://www.peterschemical.com/sodium-chloride/] Experimental Design: Table 1: Types Variables Used in Experiment Variable Description Independent 225mL of Dryl’s solution and 25mL of NaCl Dependent Speed of the Paramecium tetraurelia mm/sec Standardized Species of bacteria, temperature of the room, equipment, volume of solutions Table 2: Components of the Procedure Components of Procedure Description Level of Treatment Dryl’s solution Dryl’s solution and NaCl (25mL) Replication 1 Sample Size 18 Control Treatment 225mL of Dryl’s solution In this experiment, we observed how NaCl would affect the speed of millimeters per second of the Paramecium. The independent variable is the variable that is intentionally changed and in this case it is the solution that the Paramecium is placed in. With this variable we observed and collected data of how many millimeters the Paramecium got across per second. The dependent variable is the variable that is measured, counted or observed in the experiment. Therefore, the change of speed of the Paramecium per seconds in response to the NaCl being added is the dependent variable. The standardized variable is what is held constant and in this experiment this was the species of the Paramecium, the equipment, the temperature, and the volume of the solutions that were used. There were two levels of treatment which were first the Dryl’s solution alone and Dryl’s solution with the added NaCl. With the Dryl’s solution alone we can see how the cells react to a regular environment and then with the NaCl we can compare the results. This experiment was performed once and it’s sample size was 18. First, we placed the electrophoresis chamber on top of the stage of the dissecting microscope. Then we added 225mL of Dryl’s solution into the chamber and used a transfer pipette to transfer 3-4mL of the Paramecium to the center of the electrophoresis chamber. Then we allowed the cells one minute to adjust to the new conditions and slid the lid of the electrophoresis chamber back into place. After this, we observed the Paramecium tetraurelia underneath the microscope. Each person in the group observed a single Paramecium tetraurelia to see how many seconds it took for it to get across a certain range of millimeters. When this process was repeated it was done with 225mL of Dryl’s solution and 25mL of NaCl. Our experimental prediction was If the environment of Paramecium tetraurelia is introduced to an environmental factor then the speed per second of the Paramecium tetraurelia would decrease in the presence of NaCl compared to an environment that is not exposed to NaCl. The data from every group was collected and analyzed. Results and Data Analysis: Figure 1 which is shown below shows the change of speed compared between the control treatment and the experimental treatment. Table 3: Mean and Standard Deviation of Two Treatments of Paramecium Treatment Mean Standard Deviation Dryl’s solution 1.16666667 0.60843096 Dryl’s solution with NaCl 0.575 0.29336286 Table 3 shows the comparison between the mean and standard deviation of both the Dryl’s solution alone and the Dryl’s solution with NaCl. Table 4: T-test of Millimeters per Second of Paramecium in Two Treatments t-calculated t-critical for 95% confidence level Degrees of Freedom Confidence Level 0.00010685 2.90 17 >50% Table 4 shows the confidence levels of the results and the t-test that were analyzed. Using the mean speeds of both treatments we calculated the t-calculated and the DF. Then, from these two calculations, we looked up the t-critical and the confidence level. Discussion and Conclusions: In Figure 1, the bar graph represents the average or mean, of all the data that was collected in class. In the light blue columns we can see the speed of the Paramecium inside of the Dryl’s solution alone. The dark blue columns represent the speed of the Paramecium inside of the Dryl’s solution with the addition of Sodium Chloride or NaCl. Therefore, the dark blue columns support our hypothesis that adding Sodium Chloride to the Paramecium’s environment will decrease their speed, specifically lowering the amount of millimeters they get across per second. In table 3 we can see the mean and standard deviation of each treatment level. The mean and standard deviation of the Dryl’s solution alone was higher than when the NaCl was added. This shows that the range in which the Paramecium were moving was decreased when NaCl was present. Therefore, it can be concluded that our hypothesis that NaCl would decrease the speed is accepted. Table 4 shows the t-test for the speed of the Paramecium in both treatments. We performed a t-test and obtained the t-calculated value of 0.00010685. This value is lower than the t-critical value (2.90) obtained at a 45% confidence level with a degree of freedom of 17. Based on this we can accept our hypothesis and can conclude that the swimming speed of Paramecium tetraurelia decreases in the presence of Sodium Chloride. In conclusion, we learned that the speed of the Paramecium tetraurelia can be affected depending on what environmental factor is present in their environment. Sodium Chloride is used for many reasons and can be harmful. In this experiment, we saw how Sodium Chloride (NaCl) affected the bacteria by slowing down their speed. This can affect them because they could be eaten by prey or even most likely die if too much is put into their environment. Even though our data supports our hypothesis of how the swimming speed of paramecium will decrease in the presence of NaCl, we do not know the biochemical process that occurred and which amount of NaCl exactly slowed down the swimming speed of these cells. For future research and experiments, it would be better to study the activity of the Paramecium closely and measure very carefully which exact amount of NaCl introduced to the cells would decrease their movement.