impact of the automobile
The purpose of this investigation was to test the null hypothesis that there is no relationship between different chemical stimuli and their effect on the heart rate. To be able to see the effects of the different stimuli a Daphnia was used, or as some people call them a water flea. The results for each particular stimulus in this experiment will probably be different, some will increase the Daphnia's heart rate, and some will slow its heart rate. This will be due to the different reactions of the chemicals to the body. As most everyone probably already knows different chemicals such as caffeine will speed up your heart rate and others, as alcohol will slow your heart rate. The experiment on the Daphnia was performed as follows. The experimenters, or group members, first obtained and set up a microscope on their lab bench. Then they, used a Pasteur pipette, to obtain a Daphnia from the stock supply on the middle lab
Next, they repeated the entire process with an additional, fresh Daphnia. They then placed a cover slip over the top of the depression. After they waited one minute they turned the light back on, observed, and recorded the controlled heart rate. Daphnia have a short life span and if you were to grab one that was nearing that life span from the stock of them while conducting the experiment, you could have started out with a slower heart rate to begin with. They then placed the corner of a KimWipe on one side if the cover slip and with a Past!eur pipette they dropped a few drops of water from the "stock" pond one the other side of the cover slip and allowed the water to wick underneath the cover slip to the KimWipe. Another error could have been in the Daphnia itself. I feel that in this lab procedure as in any lab procedure that there are areas of weakness. I think that the main area of weakness would just be human error in the testing of the Daphnia, whether it be a miscount in the number of heart beats or forgetting to turn off the light when not observing them. Results Beats/Minute Beats/Minute The results of the experiment on the Daphnia as shown in the table above, conclude that different stimuli have different effects on the heart rate. I also think that there was room for other errors. Next the experimenters placed the slide containing the Daphnia on the microscope stage and used the low power objective to focus on the specimen and locate its heart. Making sure they turned off the light source when not making observations they allowed the Daphnia to become equilibrated to its surroundings for two minutes before they determined its resting heart rate. The resting heart rate was then recorded in table two of their lab print out. bench and placed it in a depression of a depression slide (making sure there was enough liquid in the depression to sustain the Daphnia). I think that in order to get more accurate data this same experiment could be done over again, but in a more controlled environment with all the Daphnia being the same age.
Common topics in this essay:
,
Beats/Minute Beats/Minute,
Daphnia Daphnia,
heart rate,
cover slip,
resting heart rate,
slow heart rate,
table lab print,
resting heart,
table lab,
relationship chemical,
slow heart,
experiment daphnia,
life span,
lab bench,
lab procedure,
|
Acceptance Essays
