Pre-Lab
None
Problem
What concentration of salt reaches the LD50 level for radish seeds?
Hypothesis
If varying concentrations of salt were tested to find the LD50 concentration of radish seeds, then the 12.5% concentration will be the lethal dose.
Materials List
·6 Petri Dishes
·60 Radish Seeds
·12 Napkins
·Concentrated salt solution
·Water
·Graduated cylinder
·60 Radish Seeds
·12 Napkins
·Concentrated salt solution
·Water
·Graduated cylinder
Procedure
1. mix the designated salt concentrations with water
2. take the paper towels and cut them into a size that will fit into the petri dishes
3. place ten seeds into the petri dish (in between the paper towels) - do to six different petri dishes
4. pour the designated concentrations of salt into the six petri dishes
5. wait a week and measure the length and number of the germinated seeds
2. take the paper towels and cut them into a size that will fit into the petri dishes
3. place ten seeds into the petri dish (in between the paper towels) - do to six different petri dishes
4. pour the designated concentrations of salt into the six petri dishes
5. wait a week and measure the length and number of the germinated seeds
Observations
- the higher the concentration, less the seeds germinated.
- the data represented below is an average of the different groups results
- some of the groups seeds did not germinate because of excess water concentration.
- germination length seems to not be connected to the salt concentration.
- the data represented below is an average of the different groups results
- some of the groups seeds did not germinate because of excess water concentration.
- germination length seems to not be connected to the salt concentration.
Data Tables and Graphs
Analysis and Conclusions
1. What appears to be the LD50 for salt for radish seeds? Support your answer with data.
100% seems to be the LD50 for this lab because that is the concentration that half of the radish seed population died.
2. Is your radicle data supported by your germination data? Support your answer with data.
The radicle data is supported by the germinated data. There seems to be a negative correlation between the concentration and number germinated. The only outlier is the 6.25% concentration with a 6.14 average.
Conclusion
Unfortunately, the hypothesis was incorrect. 12.5% was not the LD50, 100% was. Problems with the experiment could have been that the paper towels were over saturated. Also, the mixing process was a bit tedious. The correct amount of solution vs water concentration was not achieved for most of the concentrations, actually. The measuring of the volume included a bit of discretion, which may have skewed the results. The results can be viewed as fairly accurate, however. There was only one outlier in the negative trend of concentration vs. number germinated. This experiment embodies some of the experimental work done by chemists that make medicines. During the development process, experimenters must try different doses on the testing animals to determine what does would be appropriate. Once this has been approved, human experimentation follows. Without the dosage testing procedure, medicines could be lethal and ineffective.
Works Cited: "Drugs." Development & Approval Process (). N.p., n.d. Web. 12 Dec. 2012. <http://www.fda.gov/drugs/developmentapprovalprocess/default.htm>.
100% seems to be the LD50 for this lab because that is the concentration that half of the radish seed population died.
2. Is your radicle data supported by your germination data? Support your answer with data.
The radicle data is supported by the germinated data. There seems to be a negative correlation between the concentration and number germinated. The only outlier is the 6.25% concentration with a 6.14 average.
Conclusion
Unfortunately, the hypothesis was incorrect. 12.5% was not the LD50, 100% was. Problems with the experiment could have been that the paper towels were over saturated. Also, the mixing process was a bit tedious. The correct amount of solution vs water concentration was not achieved for most of the concentrations, actually. The measuring of the volume included a bit of discretion, which may have skewed the results. The results can be viewed as fairly accurate, however. There was only one outlier in the negative trend of concentration vs. number germinated. This experiment embodies some of the experimental work done by chemists that make medicines. During the development process, experimenters must try different doses on the testing animals to determine what does would be appropriate. Once this has been approved, human experimentation follows. Without the dosage testing procedure, medicines could be lethal and ineffective.
Works Cited: "Drugs." Development & Approval Process (). N.p., n.d. Web. 12 Dec. 2012. <http://www.fda.gov/drugs/developmentapprovalprocess/default.htm>.