Student Blog Post Assignment #7

Jacob Sweet
12/4/14
Period 5

Student Blog Post Assignment #7: Biodiversity and Uniqueness

A recent photo of our first two plants

A recent photo of our third and last plant

A recent photo of the tops of all of our plants

     The plants we are experimenting with are a type of Brassica oleracea, specifically Broccoli romanesco. Broccoli romanesco is a plant that eventually grows vegetables and has very dark leaves on the plant when it fully matures. By looking at the three of our plants, it is possible that its parents could have held dominant and recessive traits for leaf color since two out of three plants have a darker color of leaves (most likely the dominant trait) than the third (which would hold two recessive traits if this example were true); however, this could simply be because the plants with the darker leaves are healthier. We could predict what the plants' offspring would look like if we knew exactly what their genes were by using punnet squares with the parents' genes. By following the previous example that leaf color is a gene and the recessive one is a lighter shade while the dominant is a darker shade of it then if a heterozygous dark leafed plant bred with our light leafed plant, the offspring would have a 50 percent chance of being heterozygous and a 50 percent chance of being homozygous recessive. Those plants would acquire those traits by receiving the genes from the parents' sex cells. The genetic information in those cells is stored in chromosomes, which are duplicated, separated, and split (in that order) to create sex cells. The plant's offspring will not look exactly like the parent because some of the DNA that it has from its parents is not shown but is still passed on. Also, the plant may hold recessive traits that are not shown but there is a chance that if it breeds with another plant with the recessive trait, the child can have that trait. In addition, the plants' offspring will not all look exactly alike. This is because during meiosis, when the sex cells are being formed, the chromosomes are mixed in different ways (including crossing-over) that allow for a very large variety of possible outcomes to form in that one cell and an even larger variety when considering it can be mixed with each of the other gender's possible outcomes. Even though the varieties of Brassica oleracea being grown are closely related, they look very different. This is because they adapted in many different ways to suit the area they once lived in. So many different forms of the original wild-type Brassica oleracea could have formed because when the plant began to spread to other areas, it adapted. As it began to spread to more and more areas, the differences became quite distinct yet not distinct enough to be unrecognizable, so we now consider them as forms of the original.