Joshua Post 8

Brassica Oleracea is a species of plant that includes cabbage, broccoli, kale, cauliflower, Brussels sprouts and many more. The different types of plants all produce a different vegetable once the flower is produced. Although there are noticeable differences between each type of plant, if you take a really close look, they are actually quite similar. All Brassica Oleracea originated from one species, which is cabbage. Brassicas are the plants that The Story of The Seed project has been centered on since the beginning of the year. We have made numerous blog posts on them and done labs on them. Now a final comparison of each variation will be seen.

The anatomical part that sees the most variation from plant to plant is the leaves. In all of the plants, there is great variation in size and shape regarding the plant leaves. Some leaves are curled up, and others are flat. Others are wide while some are not, and some are longer than others. Therefore, the most variation within Brassica Oleracea plants lies within the leaves of each type of plant.

We will call this leaf, "Leaf 1". This leaf is 3 inches wide and 5 inches long. In Millimeters, it is 76 mm wide and 127 mm long. The outer contour of the leaf appears to be smooth. The ratio of length to width for this plant is 1.67 (127/76). 

We will call this leaf, "Leaf 2". This leaf is 4.5 inches wide and the length is 9 inches. In millimeters, it is 114 mm in width and the length is 228 mm. The outer contour of the leaf appears to be relatively smooth with some jaggedness. The ratio of length to 2.0 (228/114).

We will call this leaf, "Leaf 3". This leaf is 2.5 inches in width and 4 inches in length. In millimeters, it is 63 mm in width and 101 mm in length. The outer contour of the leaf is very smooth and the leaf appears to be small. The ratio of length to width is 1.60 (101/63). 

We will call this leaf, "Leaf 4". This leaf is 5 inches in width and 11 inches in length. In millimeters, it is 127 mm in width and 279 mm in length. The outer contour of the leaf is jagged and the leaf appears to be very big. The ratio of length to width is 2.20 (279/127). 

Width	Length	Ratio
Leaf 1	76	127	1.67
Leaf 2	114	228	20
Leaf 3	63	101	1.60
Leaf 4	127	279	2.20

As we can see here, there is a big variety among the sizes and ratio of length to width of the Brassica Oleracea leaves in all the plants.

The variability within Brassicas can be seen in traits of each plant. The reason why each different trait arose is due to the fact that mutations, genetic recombination, and natural selection are all acting on the brassicas. Mutations allow for increased and different traits among each plant because they are likely occurring in each plant. Genetic recombination explains that no two of the same species are going to be identical and all if the plants are of the same species. This would be Crossing over and Independent Assortment during the division process known as meiosis. Another reason for increased variability is descent with modification. This is because parents are passing down traits to their offspring, increasing the differences between each different variation.

Natural selection acting on the species and plants allows for more variations between each plant because each plant will have different needs according to the environment and natural selection will favor the traits that increase each plant's chance of survival and reproduction. There is also increased variation because of selective breeding. Humans are selectively choosing which plants to breed and cross to produce hybrids which will result in different variations among the species. There will be different types of plants.  Along with this, they will each have different genes and different genes that code for different proteins that then code for traits.

To continue, the characteristic that carries the most similarities among the Brassica plants is the color of the flowers. Although they are slightly different, they all share the same yellowish pigment in their leaves. All forms of the Brassica Oleracea carry the same color flower petals, which again, is brightish yellow.

Perfect, yellow Brassica flowers 

Perfect, yellow Brassica flowers

As we can see, all of the flowers are the yellow color. Absolutely all of the Brassica flowers exhibit this yellow pigment in their flower petals and share the same, perfect reproductive system. They all have the same structures the stamen, pistils, and anthers. This is another realm where they all share a boasting similarity. Below, we see a side by side comparison with all the leaf which exhibits the large similarity within their color.

We took samples of many different Petals from the Brassica Oleracea flowers. They all have the same rich, yellow pigment, which is why this is the anatomical part of the Brassica that show to be consistently the same within all the plants. Although we cannot take quantitative data regarding color, we see a qualitative similarity between the color of the petals in the Brassicas. 

Plant breeders, in order to change the trait that is the petal color, would have to go through a process. They would likely have to cross it with a different colored flower. The offspring would exhibit incomplete dominance. for example, If they want to make them green, they would have to cross the plants with blue flowers. They would generally have to just cross different colored flowers as flower color will exhibit incomplete dominance and will display a mix of the parent phenotypes. The way that breeders would get access to plants with different colors other than yellow. They would get these plants by searching for those plants that have experienced mutations that change their color. This would be the only way that this could be accomplished other than gene editing.