Student Blog Post #8 by Edrick Sok

1. Which part (anatomy) or characteristic of the Brassica oleracea plants seems to exhibit the most variation (greatest number of different forms)? Which part or characteristic of the Brassica oleracea plants seems to show the greatest range of variation (biggest difference between one extreme and its opposite)? Use and include data collected from multiple measurements to support your answer. The leaves of the plant seem to exhibit the most variation. For the cabbage leaves, the average of ratio from height to width is 1.55 and the average of ratio for kale leaves are about 3.5. This shows the the many ways the leaves can vary, they can be short and wide, skinny and long, or in the middle, qualitatively, the edges can show some variation as well. The part of the Brassica olercea variation that show the the greatest range of variation are also the leaves, the cabbage leaves can go from a 14:9 ratio, and the Brussels sprout leaves go starting from a ratio of 3:1.
2. Using the terms that follow, explain why you think there is so much variability in the domestic forms of Brassica oleracea: traits, selective breeding, artificial selection, genes, descent with modification, natural variations, mutations There are lots of variability in the domestic forms of Brassica oleracea because of selective breeding. Where the farmers and breeders would go and select plants (specifically the Brassica oleracea) of the same family, and breed it with a plant from the same family. Artificial selection determines what types of the plants are shown more than others, as the farmers or breeders would only go for the most desirable traits of the new plants. They favored the genes that made them delicious, bigger, easier to eat and so forth. The kids of the plants that were left to reproduce and pass down the previous traits to their offspring, called descent with modification. This increases the chance of seeing a plant with those traits out in the wild to common. There were lots of these different variations of the plants partly because of natural variation, where there are naturally different looks to the plants in nature. But, another way there are different looking plants, are because of mutations, those permanent alterations to the DNA, can be caused by the environment around them.    
3. Which part (anatomy) of the Brassica oleracea plants seems to be most consistently the same in all of the examples in our garden, regardless of how extreme the differences between other parts of the same plants may be? Why do think this is so? Again, use and include data collected from multiple measurements to support your answer.  The part of the plant that happens to be the same throughout all of the variations of the Brassica oleracea is the flower of the plants. I think this is so because, in the past, the selective breeders were looking for the variations of taste, size, and others, except for the looks of the flowers, since they had no point. The kale plant flowers had 4 petals and all the petals are aligned at a 90 degree angle. The Brussels Sprout flowers also had 4 petals that are also aligned at a 90 degree angle. The same with the broccoli.
4. What would plant breeders have to do in order to get the body part or characteristic you described above (in your response to question #3) to become much different than it is presently? The plant breeders would need to think of a characteristic that they would like to have more of. So, they have to find and choose parents that show the desired traits and breed them with each other. Then, they would take the best offspring from the two parents and repeat the process.