Published on January 20, 2008
Investigation of Brassica Rapa: Investigation of Brassica Rapa By: Becca Brooks Meredith McCurry Introduction:: Introduction: Our experiment with the Brassica Rapa consisted of using red food coloring as our experiment and no food coloring as our control. Our hypothesis was that using red food coloring, our plants would grow taller than our control. We thought the food coloring would act as a fertilizing agent and produce taller Brassica Rapa plants. The process of the plants was over a 5 week period and we also noted any change in our plants; as well as the number of pods the two groups produced at the end of their cycle. We then used the data we collected to graph and list the differences between our experiment and the control plants. Design of Investigation: Design of Investigation In our investigation we looked at the effects of red food coloring on the Brassica Rapa plant. For this investigation we posed the question, How will red food coloring in water effect plant growth? We used a control group and an experimental group, changing noting in the experimental group but, adding the food coloring to the watering reservoir once a week. We started out the investigation with each reservoir receiving 1500 ml of water, and added 1 tablespoon of red food coloring to the reservoir of our experimental group. We put sell wicks at the bottom of each unit and filled each of the units with 2 spoonfuls of soil and made an indentation for two seeds to be placed into, then we lightly packed the soil on top of the seeds and sprinkled each unit with emaculite. After planting, each unit was watered with 10 ml of water, both of our groups were placed in the same environment under heat lamps. Each day we watered all of our plants with 10 ml of water and measured our plants to record any growth. We measured the plant from where stem meets the soil to the base of the leaves. Every Tuesday we put another tablespoon of red dye into the reservoir of our experimental group and added 1000 ml of water to both reservoirs. As our plants began to grow taller we had to tie them up with string to help support their height. Once the plants began to flower we then had to pollinate them by transferring pollen collected with a bee-stick from one or more plants to the stigma of another plant. Our set-up is appropriate for the research question because we are keeping everything constant between the two groups, except for the food coloring, so that we can see if food coloring has an effect on plant growth. Results: Results On day 2 we had four plants in our experiment grow taller than the others and 5 in our control group. On day 3 all of our plants had begun to grow. On day 7 the experimental group seemed to be greener than the control group. On day 9 there was one dead plant in the experimental group. Flowers beginning to form. On day 13 there was a large growth in the experimental and control group, but another dead plant in the experimental group On day 18 pods began to form on both plants. By day 22 growth began to level off. By day 28 there was no more growth showing in either plant. Results: Results Discussion: Discussion From what we have observed from our experiment on the growth of the Brassica Rapa plant in the presence of red food coloring, is that it does not increase the growth of the plant. The evidence that supports this claim is shown in our data. The control group in this experiment always had plants that exceeded the growth or were equal to the growth of the experimental group, except between days 12-17. At this point it looked as though the experimental group would surpass the control group. After the 20th day, the experiment group reached the end of its cycle, and the control group grew another inch, then it; cycle ended.. Discussion ctd.: Discussion ctd. Although the experimental group was taller, we did find that it produced more pods. We pollinated all of our flowers equally, but the experimental group had 10 pods at the end, where the control group only had 4. Our inference is that the red dye had some effect on the amount of reproduction. However, there may be alternative reasons for what are data supports. Maybe some of the seeds were not as strong going into the soil. IT could have been that we pollinated some flowers more than others. To do the investigation again, I would pick something that can cause a drastic effect on the plants, maybe instead of adding color to the reservoir, we would add it directly to the plants, and or pollinate the plants with a red flower to see if there are any differences. Conclusion: Conclusion The data that we collected and the charts that we made, show no exceptional growth with our experiment of using food coloring. Looking at our graphs our results with the experiment and the control Brassica Rapa plants indicates very closely related growth. Our experiment lead us to conclude that there was no significant growth between the two groups. We also considered the question about using the red food coloring to change the color of our plants. But, found out in class that it would have no change do to genetic variation of the plants. Our experiment proved to us that our hypothesis was incorrect in the idea that food coloring would effect plant growth. Connection to Nature of Science: Connection to Nature of Science Our experiment on the growth of the brassica rapa we believe to be scientific because… We made observations as accurately as possible, everyday that we were with our experiment we carefully measured, watered, and recorded growth and any observations that we saw, no matter how small they were. We kept our experiment and control group as close to the same as possible with the exception of the food coloring in the experimental group. We carefully watched for any changes in the growth of our plants and noted when a plant died. Constantly made predictions and asked questions about why one plant may be growing more than the other. We talked with other people about our findings and why they may be occurring. I believe that our experiment was not truly objective because we believed that like coloring of carnations our plants would change colors, so that my be why we came up with the hypothesis that we did. We figured that the food coloring would increase the growth of the plant and slightly change it’s color. Connection To Teaching: Connection To Teaching This type of experiment would be great for an elementary classroom because your students with the help of teachers could easily grow their own plants and investigate what would happen if they changed or added something to their experimental group. To bring this investigation down to a 4th graders level, I would discuss with them what types of things we might use to change the growth of the plants. We as a class would discuss and come up with three or four things that the students could choose from to use for their experimental group. We would break the class into four groups and assign each group either the control or one of the experimental groups, with each experimental group containing a different variable. By doing so, the children are able to work in groups and come up with their own hypothesis about what might happen to their plants. Each group would observe and record their data each day during the science portion of class, and then as a class we would discuss any observations they have seen or any hypothesis they might have. As the days go by children will tend to their plants giving them the proper energy and water. When needed the children will tie their plants up to give them more support. Just as we did in class our students will also learn about pollination and how to pollinate their plants. This will also give us a chance to discuss how plants grow and what would happen if we did not transfer the pollen. At the end of the 30 day cycle our students will be able to tell you what they found does, and does not effect plant growth and why this may be true. Also students will understand the need for pollination and what would occur if pollination were to stop. Children will display drawings of their findings and brief summaries of what they observed during their experiment for the entire class to look at and discuss.