| Explore | 1. We know that plants absorb all color wavelengths except for the color that they are; for example, a green plant absorbs all colors except for green. Through photosynthesis, plants take in CO2 and produce O2 as a by-product. We also know that the roots of plants serve as a source for water and nutrients to be used and absorbed by plants. 2. Roots also serve as a way of anchoring a plant into the ground as well as how to absorb water and nutrients. The O2 produced by plants is a result of H2O being split for the electrons needed in photosynthesis, the O2 is just the leftover products that were not needed. 3. How do environmental changes affect the growth of plants? How do plants know how to determine growth direction? What chemical changes are taking place in order for plants to undergo each of their life stages? |
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| Research Question | The purpose of this experiment is to study the affects of different solutions on celery curvature. We want to maximize the bending. We will be comparing salt and alcohol solutions at different concentrations. How does salt affect the cells in the celery? How does alcohol affect the cells? Do low or high concentrations work best? Which solution has a greater affect? Considering salt and alcohol dehydrate us as humans, we decided to use these in our experiment with the celery so it fits our topic. |
| Predictions | We hypothesize that the higher concentrations will work best in for both solutions. We also hypothesize that the salt solutions will have a greater affect on curvature than the alcohol solution. Our alcohol test will be more experimental for us because as a group, we aren't sure how it will affect the cells. For the salt solution, we expect that osmosis will take place. We believe that the water in the cells will move out into the solution because it is more concentrated and the cells will shrink, causing a change in shape. |
| Experimental Design | Update: After trial 1 we decided to do another trial. In trial 2 we followed the same procedure but we changed the concentrations of the salt and alcohol to (10%, 20%, 30%). We also did a third trial that consisted of (5%, 10%, 15%) concentrations. We also were not able to keep our trials at a constant temperature in the fridge like we had hoped. For our groups' experiment, we will be using three different percentages of isopropyl alcohol (25%, 50%, 75%) and three different percentages of saltwater solution (25%, 50%, 75%) and a constant stalk in just a plain water solution. Procedure: We will collect 2 stalks of celery to place into each of our solutions The solutions will be in 600ml beakers and the celery will be freshly cut before being placed in the solution. The celery will be kept in the fridge at a constant temperature so there is less outside factors acting on the rate of wiltation. Thus meaning less room for error. The celery in the solutions will be left in the fridge for a total of 7 days (this could change based on the results we are seeing after the week is over) The variable that is being tested for is the rate of celery bending. Our constant will be the celery in the plain water solution. We also will be keeping the number of solutions the same throughout and the length of each celery stock the same. All solutions will be kept in the exact same environment (the fridge). Our data will be recorded by, someone each and measuring the angle of the celery to see how much they have changed. |
| Conclusion | Data: Trial 1- We used 25%, 50%, and 75% concentrations of salt solution where 25%= 25g salt & 100g water. We concluded that the concentrations we used were much to high. The salt did not dissolve completely in the solution.The salt solution made the celery completely wilt and fall apart and it did not hold any shape. The (25%, 50% and 75%) alcohol solutions preserved the celery but there wasn't much change besides the celery being bleached. Trial 2- For this trial we used (10%, 20%, and 30%) concentrations. The salt dissolved more in the solution but still not completely. Again, the salt solution did not make the celery hold it's shape and it once again wilted towards the part of falling to pieces in the solution. However the alcohol worked better in this trial, the celery had a rubbery feel. The shape was not curved, it was more sturdy. Trial 3- We used concentrations 5%, 10%, and 15%. The salt dissolved completely in these solution. The celery in this trial for the salt solutions did not fall apart as seen in the previous trials. It held its shape much better but still did not have the curvature that we were hoping for. The alcohol solutions on the other hand for this trial did not preserve the celery as well as in the previous two trials. They completely lost all shape and looked much like our control celery that was just in tap water. The control celery had the same result each and every trial, it became brown and mushy (almost dead looking) and started to disinegrate away. We believe this was due to the alcohol becoming so diluted it no longer preserved the celery as it had done previously or how the salt continued to preserve it. Conclusion: Overall our final trial seemed to give the most promising results. The celery in the salt concentrations of 5%, 10%, and 15% held their shape best without it wilting so much it fell to pieces. We wouldn't go as far to say that our trials were a success because there was minimal curvature in the shape of the celery. This was true for all trials. In the beginning the high concentrations wilted the celery too fast. The lower concentrations worked better, but we still did not get the results in curvature that we expected. We believe that the solutions were still too high in the end and the process of osmosis and absorption occurred too drastically in a short amount of time. Future experiments could include other factors like temperature and environment. We believe that keeping it at a constant temperature, either hot or cold, could help with holding the celery's shape. We also think the concentrations of salt could be lowered even more to get better results. The concentrations of alcohol should stay in the 15 percentage range since that was the concentration that did not fully wilt the celery so that it stayed at a nice balance of bendy but also crunchy so that it would still hold its curved shape. Some things we would change in our experiment if we could do it again would be; amount of time the celery was left in the solutions, concentrations of solutions, the type of substances we were using to wilt the celery, and the enviornmental conflictions. We believe that we may have left the celery in the solutions for too long (7 days for each trial) and that could have skewed our data on how much each celery piece wilted. Perhaps less days could help prevent the celery from falling apart as it did in many of our trials. As for the concentrations of the solutions and the enviornmental conflictions we think that the salt concentrations should continue to be lowered and the alcohol concentrations should stay at about 15%, as we mentioned before. The enviornmental conflicts would be to keep the celery at a stable constant temperature as well as preventing evaporation or contamination from outside sources. Finally, we think it would be very interesting to see what would happen if we tested other solutions in this lab. For example we chatted about testing out vinegar, sugar solutions, gas, and maybe some of the commercially used everyday household solutions like juice, soda, milk, or dishsoap. All in all we had fun with this experiment and think that there are plenty more ways to set it up in creative and intuitive ways |
| Investigation Theme | CEL |
| Grade Level | Undergraduate Students |
| School Name | Emporia State University |
| Session | Fall 2018 |