| Explore | Up until this point, it is known that the relationship between plants and hairs is critical to the plant's survival in specific climates. The hairs, or trichomes, insulate the plant’s leaves from the cold temperature and help prevent water from evaporating during times of wind and heat. They reflect the sun's radiation and help lower the plant's temperature. The knowledge from previous experiments showed the number of trichomes can increase drastically in just one generation through artificial selection, namely directional selection. |
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| Research Question | How does sugar water, as opposed to regular water, affect a plant's ability to grow and produce hairs? |
| Predictions | A possible outcome for this study would be the average height of the plants increasing because the amount of sugar in the water will increase the amount of glucose the plant intakes which will create more energy for it to grow. |
| Experimental Design | Independent & Dependent Variables -Independent: Sugar water -Dependent: Number of hairs on each plant Procedure -Split groups into control and experimental groups -Each group will plant their seed the same way we need with our hairy plants; wet soil into the top half of the water bottle leaving about 2 cm uncovered, then fertilizer on sprinkled on top of the wet soil and covered with a thin layer of wet soil, then dry soil is placed on top of the wet soil and fived holes are poked into it with a colored pencil, then after, a seed is placed in each hole and is covered with dry soil all the way to the top (a wick will be tied to the cap of the water bottle). -Then after, water is placed into the bottom half of the water bottle (type of water will differ) -Control group will just have regular tap water while the experimental group will have sugar water instead of regular water. - For the first week, the wick will not be placed into the water but it will be the following week -Collect data and compare from every group in the control and experiment each week Methods to ensure only one variable is changed between the control and experiment -Same amount of light given -Same sugar water used for control groups -In the same environment Data Collection Methods -Collect the number germination -Stem height -Color of the stem -Number of hairs -Split groups with the control and experiment |
| Conclusion | Two different Views: 1) Although both environment and genetics can have a significant effect on an organism's body, in this case, genetics had a bigger effect on the organism. When selective breeding was used, there was a 104% increase in hairs from generation 1-2. When using sugar water, there was only a 60% increase from the experiment group to the control group. This shows that the plants with selective breeding increased hair 73% more than the sugar water in just two generations, thus making genetics more effective in changing an organism’s body. 2) The environment can have more effect on an organism's body. Environment forces an organism to adapt, causing changes in their bodies. These changes are what help the organism to survive in their environment. These can then be passed onto their offspring. In the three generations of selective breeding, there was a sudden increase in the second generation, while in the end, there was only a slight increase. In this experiment, there was a 60% decrease in hairs–from the environment! |
| Investigation Theme | BRASSICA |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | Service High School |
| Session | Spring 2018 |
| About this Project | This class nicely related their Planting Science investigation of Brassica genetics in different environments with a separate, year-long project, of selectively breeding Fast Plants for increased hairiness. By comparing the two data sets, students were able to quantify a nature versus nurture explanation. This class nicely related their Planting Science investigation of Brassica genetics in different environments with a separate, year-long project, of selectively breeding Fast Plants for increased hairiness. By comparing the two data sets, students were able to quantify a nature versus nurture explanation. In the Planting Science experiment, this class grew Fast Plants in water and a 98 grams sucrose/L (just like a certain soft drink) solution and counted hairs on the first true leaves on the plant for a quantitative trait. The plants in sugar water grew 60% more hairs than the control in plain water. This was interesting, because, through three generations of selective breeding (using pollen from the hairiest plants in class and replanting seed from the hairiest plants grown) the class was able to increase average hairs per plant 104% in three generations. This allowed the student to compare the two experiments and have a clear distinction between the effects of environment and the effects of genetics on a group of organisms. Besides tying into an existing year-long project, the Planting Science experiment also sparked a scientific argument: yes, the selective breeding increase hairs more, but that was over three generations, not just the one generation that was exposed to sugar water. More experiments are needed! |