Drafts

Cooperatively breeding passerines are targeted by parasitic species more frequently and due to their heavy cost, defense mechanisms in the form of mobbing have also evolved in response to this.  Feeny and his team initially began their study due to the overlapping concentrations of cooperatively breeding passerine species and parasitic species in australian and african regions.Furthermore, the driving force between these interactions is unclear and they note that this may be a coincidence secondary to the unpredictable environments they both inhabit. They proposed that 3 non mutually exclusive theories that could have driven the evolution of this behavior: 1. The parasitic offspring receive the greatest care, cooperative nests are more easily visible due to their activity and finally cooperative breeding may be selected for as they can better defend their nests from parasites.

For our experiment, we will assign each of the eight groups from the Writing in Biology 312 course there designated floor in either Morrill building III or IV. They will observe and take note of five different surroundings in the window sills located in classrooms available and open to the students. They will collect data on the presence of different small organisms such as insects or arachnids. Insects or creatures will include fruit flies or other flies, carpenter bees, spiders, or ants. Exact location of the five window sills will be taken note of. In addition, whether the environment was hot or cold will be recorded. They will count insects or creatures and data collected will be inserted into the chart in Appendix A. Groups will remain in their designated floor and examine what they see overall. At the end of their observations, each group will submit their data into a document excel sheet. After all data has been recorded and gathered an analysis will be made to come to a conclusion of which Morrill building will be a great environment for many insects that surround us.

Plants photosynthetic abilities are determined by its chlorophyll. Chlorophyll are the subunits responsible for photosynthesis in plants, as well as the pigmentation of the plant. The color of chlorophyll is determined by the wavelength of visible light that it does not absorb. Chlorophyll a is the most abundant chlorophyll in plants and is the reason most plants appear green. Chlorophyll a absorbs red light and blue light, while reflecting green/yellow light. This reflection is what we see when we look at the color of a plant. There are many types of chlorophyll, each specializing in different wavelengths of light. This causes them to portray unique colors and define the plants that have them. 

Mutations are constantly occurring in our genome from generation to generation. They lead to genetic variation between individuals of a population. Not all mutations are equal though, and most mutations go unknown and unseen by most of the population. This is because there are several different types of mutations that can occur. One of these mutations is a missense mutation, which results in a change in one DNA base pair. This causes one amino acid to become another and can either be harmful or unnoticeable. Nonsense mutations are when an amino acid is changed into a stop codon, prematurely ending the protein. This can be catastrophic for the protein involved. Finally, insertions or deletions result in frameshift mutations, which change every amino acid after the affected area. This can completely change protein function and be devastating. 

Genetic drift is a unique evolutionary force. Genetic drift acts entirely random and has no bias towards any phenotype. Populations that undergo genetic drift experience fluctuating phenotype and genotype ratios. What really sets genetic drift apart is the it always moves towards fixing a certain allele. It can be either the dominant or recessive since it is random selection. After a certain number of generations only undergoing genetic drift there will only be one allele type left. This is because as individuals are selected to reproduce, allele frequencies change. Even if both alleles start out equal, one will be favored over the other due to random chance. This will lead to a divergence that eventually leads to allele fixation. Genetic drift causes populations to differentiate. 

Phloem sap is difficult for scientists to study. This is because plants are highly evolved to minimize phloem loss in the case of external damage. When a sieve tube is penetrated, it signals throughout the plant, triggering the release of callose which clogs the pores of the sieve plate. This causes all phloem movement through the sieve tube to stop. Luckily, scientists have figured out two ways to study the phloem uninterrupted. The first is to use a normal extraction tool that has been coated in an anti-slime. This allows scientists to observe the plant’s phloem without the interruption of sliming. The second way is by zapping aphids off of the plant after they have inserted their stylet. Aphids are able to access the phloem without triggering the release of callose. By removing the aphid without removing the stylet it acts as a phloem pump. Both of these methods are effective at extracting phloem from a plant without sliming occurring. 

The cell wall provides many functions to the well being of a plant. First, the cell wall is strong and durable. This helps to protect the plant from the environment as well as pathogens. This durability also helps to support the plant during growth. If it wasn’t for the strength of the cell wall, the plant would wilt and not be able to grow upright. The strength of the cell wall also helps to anchor the plant to its environment. This allows the plant to survive without being easily uprooted. Aside from mechanical function, the cell wall also aids in transporting water and nutrients throughout the plant, as well as signaling and transferring information throughout the plant.

There are three major components of the cell wall. These components are cellulose, hemicellulose, and pectin. Each of these components is made up of different monomers. Cellulose consists of β (1-4) linked D-glucose. Hemicellulose consists of glucose, xylose, mannose, galactose, rhamnose, and arabinose. Finally, pectin consists of α-(1-4)-linked D-galacturonic acid. Of all of these components in the cell wall, cellulose is the most abundant and strongest. 

Three additional samples of live LLC-Pk1 cells were treated with fluo-4. Control group cells were submerged in HBS buffer, while ATP and bradykinin experimental groups were submerged in calcium free HBS buffer, eliminating significant extracellular calcium. Cells were then treated with respective stimuli, and sub sequentially treated with ionomycin. Time lapse images were taken at 10X magnification for 270 s (1 frame every 2s) to capture the cellular response to the stimuli and ionomycin via fluorescent activity (Figure 4). Fluorescence intensity versus time data reveal patterns of fluorescence intensity (and therefore, cytosolic calcium level) fluctuation based on specific stimuli introduced to the extracellular space (Figure 2). Control sample (ATP/ionomycin treated cells in HBS) exhibited an oscillating fluctuation in fluorescence intensity over time (Figure 3A) and did not demonstrate a relative fluo-4 intensity increase after ionomycin treatment (Table 1). Bradykinin experimental cells   demonstrated no response over time after being treated with stimuli, whereas a majority of ATP experimental cells exhibited a response (0/101, 152/154, respectively, Table 2). However, after ionomycin introduction, both bradykinin and ATP experimental cells experienced an increase in fluorescence intensity (800, 500, respectively, Table 2) for the remainder of the time lapse imaging (32s, Table 2). Differences in control and ATP experimental groups are noted in the duration of initial calcium spike (12 s, 8 s, respectively, Table 2), avg. time to first peak of cells responding to initial stimulus (42 s, 32 s, respectively, Table 2) and increase in intensity at peak of response to the stimuli (240, 850, respectively, Table 2).

Four samples of live LLC-Pk1 cells were treated with fluo-4 (a calcium sensitive fluorophore). Each sample was then exposed to a different stimulus while submerged in HBS buffer, Time lapse images were taken at 10X magnification for 120 s (1 frame every 2s) to capture the cellular response to the stimuli via fluorescent activity (Figure 3). Fluorescence intensity versus time data reveal patterns of fluorescence intensity (and therefore, cytosolic calcium level) fluctuation based on specific stimuli introduced to the extracellular space (Figure 1). Cells treated with HBS (control group) expectedly demonstrate no significant fluctuation in fluorescence intensity overtime, and therefore were not able to quantitatively analyzed any further (Figure 1), Cells treated with bradykinin appear to have a delayed rise in fluorescence intensity over time (44s, Table 1) whereas ATP treated cells appear to have an immediate and oscillating fluctuation in fluorescence intensity over time (3s, 18s, respectively, Table 1). Only a small number of cells responded to bradykinin introduction with an increase in fluorescence intensity, while a majority of the cells treated with ATP demonstrated a response (11/154, 97/99, respectively, Table 1). Additionally, the relative increase of fluorescence intensity in cells treated with bradykinin appears to be much larger than that of cells treated with ATP (589, 331, respectively, Table 1). Vasopressin treated cells demonstrated no fluorescent fluctuation over time, and therefore were not able to be quantitatively analyzed any further (Figure 1). Reasons for this absence of an expected response are detailed in the discussion.