Abstract
In this lab, we took six small petri dishes and filled them all up with different concentrations of saltwater. We placed radish seeds in the petri dishes and then waited two days to see which petri dishes would allow the seeds to germinate or not. As I predicted, the lower concentrations of saltwater (water with no or lessser salt in them) allowed more, or all of the seeds to germinate compared to the other dishes.
Problem
What will the LD50 of radish seeds be if we soak them in a saltwater solution for two days?
Hypothesis
If we add more salt to the solution of water we place the seeds in, then the radicle length of the cotyledon will be shorter.
Parts of the Experiment
Control Group: Petri dish with no salt in the water
Experimental group: Dishes with salt in the water
Independent variable: Amount of salt in the water
Dependent variables: Number of germinated seeds and their radical lengths
Controlled variables: Number of seeds, napkins used, amount of liquid solution
Materials
6 petri dishes, 6 seeds for each dish, 12 napkins, water, graduated cylinder, salt water solutions
Method
1. Use the graduated cylinders and test tubes to prepare the various concentrations.
2. Label all six petri dishes with your group number, the dish number, and a percent concentration of chemical:
-Dish #1: 0%
-Dish #2 6.25%
-Dish #3: 12.5%
-Dish #4: 25%
-Dish #5: 50%
-Dish #6: 100%
3.Put two napkins together and cut them so that they fit into the petri dish.
4. Put on the satety goggles and latex gloves. Carefully pour the chemical soultions onto the napkins, making sure to match the numbers and concentration percentages of the dish.
6. Repeat steps 3-5 for the other dishes.
7. Place the seed dishes in a stack, lying flat with the seeds up. Put the seeds in the spot
In this lab, we took six small petri dishes and filled them all up with different concentrations of saltwater. We placed radish seeds in the petri dishes and then waited two days to see which petri dishes would allow the seeds to germinate or not. As I predicted, the lower concentrations of saltwater (water with no or lessser salt in them) allowed more, or all of the seeds to germinate compared to the other dishes.
Problem
What will the LD50 of radish seeds be if we soak them in a saltwater solution for two days?
Hypothesis
If we add more salt to the solution of water we place the seeds in, then the radicle length of the cotyledon will be shorter.
Parts of the Experiment
Control Group: Petri dish with no salt in the water
Experimental group: Dishes with salt in the water
Independent variable: Amount of salt in the water
Dependent variables: Number of germinated seeds and their radical lengths
Controlled variables: Number of seeds, napkins used, amount of liquid solution
Materials
6 petri dishes, 6 seeds for each dish, 12 napkins, water, graduated cylinder, salt water solutions
Method
1. Use the graduated cylinders and test tubes to prepare the various concentrations.
2. Label all six petri dishes with your group number, the dish number, and a percent concentration of chemical:
-Dish #1: 0%
-Dish #2 6.25%
-Dish #3: 12.5%
-Dish #4: 25%
-Dish #5: 50%
-Dish #6: 100%
3.Put two napkins together and cut them so that they fit into the petri dish.
4. Put on the satety goggles and latex gloves. Carefully pour the chemical soultions onto the napkins, making sure to match the numbers and concentration percentages of the dish.
6. Repeat steps 3-5 for the other dishes.
7. Place the seed dishes in a stack, lying flat with the seeds up. Put the seeds in the spot
Data
Specific Analysis
1. What appears to be the LD50 for salt for radish seeds? Support your answer with data.
-It appeared that between the 25% and 50% concentration was where the LD50 was. Around 37% according to my line graph.
2. Is your radicle data supported by your germination data? Support your answer with data.
- Not necessarily, as you can see in my graph with the radicle lengths and the percent seeds germinated, even though the seeds all did germinate in certain parts, the length depended on the salt concentration. There may have been enough water for the seeds to germinate, but not to thrive among the saltwater.
Conclusion
In conclusion, my hypothesis turned out to be correct. The more salt that was added to the solution, the worse the seed germination and radicle length got. Although we only tested the LD50 of seeds in water, I think that this could be an inaccurate way of measuring the death levels of toxicity on perhaps a person. I think this because even in my experiment, different numbers came out of the different percentages of germination and it all depended on that particular seed. According to my citation article, drug companies feel that this classic test should no longer be used in clinical trials. It's too risky to assume that half of the people you test could die and it all seems to depend on the person.
1. What appears to be the LD50 for salt for radish seeds? Support your answer with data.
-It appeared that between the 25% and 50% concentration was where the LD50 was. Around 37% according to my line graph.
2. Is your radicle data supported by your germination data? Support your answer with data.
- Not necessarily, as you can see in my graph with the radicle lengths and the percent seeds germinated, even though the seeds all did germinate in certain parts, the length depended on the salt concentration. There may have been enough water for the seeds to germinate, but not to thrive among the saltwater.
Conclusion
In conclusion, my hypothesis turned out to be correct. The more salt that was added to the solution, the worse the seed germination and radicle length got. Although we only tested the LD50 of seeds in water, I think that this could be an inaccurate way of measuring the death levels of toxicity on perhaps a person. I think this because even in my experiment, different numbers came out of the different percentages of germination and it all depended on that particular seed. According to my citation article, drug companies feel that this classic test should no longer be used in clinical trials. It's too risky to assume that half of the people you test could die and it all seems to depend on the person.