rmirley's blog

Global warming is a major concern for modern day society. As global temperatures rise, the glacial caps melt and species of plants and animals adapted to a specific climate are put at risk of extinction. A major contributing factor to this global warming is a process called the greenhouse effect. As human activity increases, so does the global CO2 levels. CO2 is a heavy gas, meaning that it will pass visible light, while reflecting infrared light. This causes the CO2 in the atmosphere to build and retain heat. The rapid increase in CO2 levels is one of the major causes of the increase in the global temperature.

Plants exhibit both primary growth, as well as secondary growth. For primary growth the plant elongates, growing out of the soil and towards the sun. This type of growth is fairly rapid in order to maximize photosynthetic output. Secondary growth is when the plant widens. In order to do this, the plant requires a layer of tissue called the vascular cambium. The vascular cambium is between the interior xylem and exterior phloem. This growth forms layers of secondary vascular tissue that keep the phloem and xylem in the correct place. These rings can be counted to determine the age of the plant. 

Plants transfer water and nutrients in the plant through the phloem, which is composed of sieve tube elements and sieve plates. If the sieve tube element is damaged the plant is at risk of losing all of the nutrients and water flowing through this. To combat this the plant secretes callose, which blocks the pores in the sieve plate and stops flow through the damaged sieve tube. This has made studying the phloem of a plant particularly difficult. Interestingly enough, and insect breed called aphids have evolved to be able to penetrate the sieve tube without triggering the secretion of callose. By blasting the aphid from the plant while leaving its extractor in place, we have been able to study the phloem of the plant in more depth than ever before. 

Sieve tube elements and sieve plates are two completely different elements in a plant, despite the similar names. Sieve tube elements are components that form end to end to create sieve tubes, while sieve plates form between the sieve tubes. The sieve plate has micropores in it that connect the adjacent sieve tubes, allowing for material exchange between each tube. Normally this would pose a risk to the plant because one damaged sieve tube would cause the whole plant to “bleed out” as all of the water and nutrients it was transporting would be lost. To combat this, the plant can detect when the sieve tube is damaged and secrete callose, which can seal the pores in the sieve plate to stop nutrient and water transfer in that tube. This process acts much like coagulation in the human body.

 Leaves usually display a uniform color across the whole leaf. The pigmentation of the leaf is caused by the chlorophyll. The chlorophyll is what absorbs the light energy for photosynthesis. As can be seen by the leaf, the pigmentation is found throughout the leaf, covering as much area as possible. This is due to the sieve effect. The higher the concentration of pigmentation, the more light that is absorbed. However, if the leaf concentrates more pigment into one area, it lowers pigmentation in another area. By lowering pigmentation elsewhere, the leaf actually absorbs less light than if it had a uniform concentration throughout. This is why leaves are a consistent color across the whole leaf. 

Retrievers are either black or brown depending on whether TRP-1 and TRP-2 are synthesized. If TRP-2 and TRP-1 are synthesized then the retriever is black, but if only TRP-2 is synthesized then the retriever is brown. In the case of a yellow lab however, neither TRP-1 or TRP-2 are synthesized. This is due to a mutation in the MSH gene that changes its conformation. Because of the change in conformation, the MSH can no longer bind to the MSH-R. The MSH-R is what signals to produce the TRP-1 and TRP-2 that causes pigmentation. This is what causes the hair of the yellow retriever to never become pigmented.

Retriever dogs have three distinct phenotypes. There is the black phenotype, the brown phenotype, and the yellow phenotype. The difference in expression between the black and brown phenotype comes down to the production of two enzymes: TRP-1 and TRP-2. All retrievers produce tyrosine, which when reacted with tyrosinase forms dopaquinone. TRP-2 then reacts with the dopaquinone to create the brown pigment, which then reacts with TRP-1 to form the black pigment. Black is the dominant color of the two because it takes only one signal to produce both TRP-1 and TRP-2. There is a mutation in the recessive allele that causes only TRP-2 to be produced, causing the pigmentation to halt once it reaches the brown pigment. 

Finally, the multipanel figure was constructed. There were three main panels consisting of a picture of the full plant, a picture of a close up of the flower, and the figure showing the plant’s origin. The multipanel figure was set up so that there was a long image on the left side and two stacked images on the right side. The long image on the left, labeled A, was the photo of the entire plant. The photo in the top right, labeled B, was the close up photo of the flower itself. The bottom right photo, labeled C, was the figure that shows the plant’s origin. For the labels A, B, and C, the letters were in the top left of the photo they were labeling, in a white box. The letters were in 72 font size and only occupied a small amount of space. 

Next, a figure was created to show the origin of the species and where it mostly grows. The figure was created on amcharts.com under the visited countries section. The Blc Momilani Rainbow is found mostly in tropical climates in South America. As such, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, Panamá, Colombia, Ecuador, Perú, Venezuela, Guyana, Suriname, French Guiana, and Brazil were highlighted on the map. 

The chloroplast is composed of several different parts. First, it has an outer membrane called the outer chloroplast membrane. This is then followed closely by an inner chloroplast membrane. Inside the membranes there are stacks of folded thylakoid membrane, called grana. between these folds is an interior called the lumen. Not all of the grana line up, leaving exposed sections called stromal lamellae. All of this is suspended in a fluid enterior in the chloroplast, called the stroma.