Having study natural selection and artificial selection we wanted to select for a trait on the plant Brassier ARPA. We hypothesized that the leaf density is heritable and veritable. After our experiment we were able to conclude that our hypothesis was refuted because our average leaf density in our daughter population increased. Introduction: We are artificially selecting for a trait in the plant Brassier ARPA. ( Wisconsin Fast Plant).
Brassier ARPA has been artificially selected for many generations under countless of experiments, where there have been different types of Brassier ARPA hat have come emerged ( Encyclopedia of Life, 2005). Artificial selection is the process of manipulation of animals and plants is the process of manipulation of animals and plants breeding by humans to select a particular desirable trait in a population (Freeman, 2005). The different breeds of domestic dogs goes through artificial selection because we select individuals with those desire traits to reproduce which causes different breed in dogs ( The American Heritage Dictionary).
Natural selection is the process by which organisms that are adapted to environment tend to survive and pass down their genetic traits that increase the umber of successful generations while those who are less adapted to the environment tend to not survive and reproduce ( Biology 171 Laboratory Manual). Animals that are best suited for the environment for example dinosaurs before they were extinct were the animals that were suited to the environment because they were able to adapt because they were able to survive and pass down their biological traits to their children.
We are studying artificial selection and natural selection on the plant Brassier ARPA. We observe that we can artificially select for a specific trait that we want to assure on the plant Brassier ARPA. While making these observations we are able to question can manipulate the original population of Brassier ARPA to have a trait that is heritable to their daughter population. We hypothesized that the leaf density is heritable and variable.
We predicted that if we selected ten plants of the parent generation closest to the average density of leaves, then all the offspring will have a density closer to the original average and stabilization will have occurred. Materials and Methods: To begin the experiment we used two cell flats and trays that have 98 cells total to old the 98 plants for each treatment. We took the cell flats and placed them on top of the trays cut out the first cell of each tray to have an opening for watering. We then filled each cell in the trays with soil, made sure to pat down the soil to get rid of air bubbles.
Then, we took a pair of forceps and planted one seed 3 mm deep into the soil for each cell. Once we planted the seeds we watered the plants with a cup and measured the water to be 3 CM. After the first day we watered the plants every Monday, Wednesday, and Friday up to 1 CM. After fourteen days passed we counted he number of leaves of each plant and divided it by the height to find the density for each plant. We selected the ten plants that were closes to the average leaf density from our original population for our parent plants of our experimental treatment.
The control treatment, chose their parent plants by choosing the plants that were the same as the original population. This allows us to see if anything was manipulated from the original population of the plants. Once the plants start to grow and flowers start to blossom we select the ten parent plants that are closely related to the original population to pollinate. To know which ten to select we calculated the leaf density for each flower and found the ten closets the original population and selected the plants.
Once the ten were selected we cut out all the other plants and Just left the ten selected plants to be pollinated. To have a successful pollination we had to pollinate the highest point on each plant first and pollinate each high point on each plant. Once the highest point was pollinated the we pollinate the second plant of each leaf and continue this for two more times. If there were any new flowers of buds growing from the plant that were to there before we pollinated we had to cut them because new flowers would emerged that were not from the original population.
After the seeds have been pollinated, we stopped watering the plants. We then counted the number of leaves of each plant and divided it by the height to see is the trait was heritable to the daughter population. Our independent variables was the leaf density of the ten selected parent plants. Our dependent variables was the leaf of our offspring generation. Our stabilizing variable were the temperature, amount of water and light. Results: Our results showed that the leaf density was not a heritable trait between the parent population and the daughter population.
In Figure 1 the average leaf density of the stabilizing group the original population of the plants in n=74, the parent population is n=10 and the daughter population is n=54. In Figure 2 the average leaf density of the control group is the original population is n=84, parent population n=10, daughter population n=32. Figure 3 the original population of the stabilizing group is n=84 and the daughter is n=32. In figure three the control group had an original population of n=74 and the daughter population is n=54.
Figure 1: Stabilizing Group Figure 2: Control Group Figure 3: Stabilizing Group Figure 4: Control Group Discussion: As we tested out our experiment we were able to conclude that the leaf density is not a heritable and variable trait. Our results concluded that the leaf density from the original population to the daughter population is not a heritable trait that was passed down. As we tried to select for the ten parent plants from our original population to plant, we had problems planting the ten plants because some of our lands would break so we had to chose the next on closets to parent population.
This made our results different because we were not able to choose the exact ten parent plants that were closest to the original population. Some errors in our experiment were that we could not get the exact same plants from the original population. To do this experiment again there are only certain things that we as a group could do different, there should be an equal amount f participation between all group members, group members should distribute the work of the experiment among each other so that no one person is given the same Job each time.