Writing in Biology

Each environment chamber will consist of a styrofoam box with a lid, allowing for access to the enclosures and insulation of temperature. A thermometer will be attached to each environment chamber to monitor temperatures and ensure they are constant. The room temperature chamber will have not have any additional materials. The other two environments will have modifications that allow for the control of temperature above and below room temperature (See Figure 2). For the cool condition, an additional layer of plastic will be placed above a layer of ice. The layer of plastic will have a hole in it to allow for replenishing of ice. Melted ice will drain from a hole at the bottom of the environmental chamber into a receptacle. The ice will ensure that the chamber will maintain a cold temperature for the enclosures within to be subjected to. We will determine the ideal interval for changing the ice to ensure constant temperature prior to beginning the experimental procedure. For the warm condition temperature chamber, a heat lamp fixed above the box will maintain it at 25°C. Like the cool condition, we will determine how far to place the heat lamp from the temperature chamber for a constant temperature prior to the introduction of the enclosures.

There are some fish species which reproduce through parthenogensis. This may come in at least two froms, gynagenesis and hybridogenesis. One example of gynagenesis is with fish carrying monocha (M) and lucida (L) genes. Some females are triploid and carry MLL. These females will produce a triploid egg, also MLL. A diploid LL fish will release its L sperm in order to "fertilize" the MLL egg. There is actually no genetic transfer in this process, the sperm only stimulates the MLL egg. Once successfully stimulate, the egg activates and a new triploid MLL female (yes always female) fish is born. So where do males come from if all that is produced from this process is females? The normal diploid population, which is favored by diploid males. Therefore, there are two seperate populations. A diploid population of both males and females and a triploid population of all MLL female clones.

Each environment chamber will consist of a styrofoam box with a lid allowing for access to the enclosures and insulation of temperature. A thermometer will be attached to each environment chamber to ensure constant temperature. The room temperature chamber will have not have any additional materials. The other two environments will have modifications that allow for the control of temperature above and below room temperature(See Figure 2). For the cool condition, an additional layer of plastic will be placed above a layer of ice. The layer of plastic will have a hole in it to allow for replenishing of ice. Melted ice will drain from a hole at the bottom of the environmental chamber into a receptacle. The ice will ensure that the chamber will maintain a cold temperature for the enclosures within to be subjected to. For the warm condition temperature chamber, a heat lamp fixed above the box will maintain it at 25°C.

To determine the web production in each environment, the plastic cup enclosures will be weighed again once five days elapses. The initial weight will be subtracted from the final weight, which will give us the weight of each spider web produced over the course of the experiment. The difference in weight between the temperature groups will then be compared. Finally, a statistical analysis will be run to see if there is significant correlation between temperature and spider web production.

Previous research has found that web production is greatly decreased in the cold, thus we expect the cool condition to have the lowest web mass. This research concerns the effect of temperature on web production and can be related to the global shift in temperature. Global warming is altering the climate and resulting in temperatures that would be considered abnormal in the past. As a result, the behavior and localization of organisms will change. We plan to apply this to cellar spiders to observe how global temperature change may alter their behavior, specifically web production.

Our research aims to observe the effect of temperature on the production of cellar-spider webs. We plan to include nine spiders and evenly split them across our three conditions. Each spider will be kept in an enclosure based on a design from previous research and placed into one of the conditions. The enclosures will be weighed before they are put into their respective conditions and again when five days elapse. The three temperature conditions utilized for our experiment will include a cool condition, a room temperature condition, and a warm condition. These conditions will be kept at a constant temperature with the utilization of styrofoam boxes for insulation, a heat lamp for the warm condition, and cycling of ice for the cool condition.

 

The aim of this experiment was to use wild type and mutant strains of Chromobacterium violaceum to explore N-acyl-homoserine lactone (AHL) based quorum sensing in Gram negative bacteria. AHLs are signal molecules produced by Gram negative rods. They regulate antibiotic synthesis, expression of virulence genes, biofilm formation, and several other cellular activities. Two genes are responsible for AHL mediated gene regulation. One encodes a transcriptional regulatory protein (R gene), and the other encodes the enzyme AHL synthase (I gene). The presence and proper functioning of these two genes is essential for the target genes to be transcribed. AHL synthase produces AHL molecules, which are classified by their side chain length and molecular structure. AHL synthases differ between each genus of bacteria, and produce AHL molecules that are slightly different from each other. Most regulator proteins that bind AHL molecules are specific for a certain AHL structure, but some can bind more than one type of AHL. This can create the phenomenon of cross-communication between different species of bacteria. This experiment was done to explore quorum sensing in Gram negative bacteria and determine if different species of bacteria could communicate with C. violaceum.  

A-site: the ribosomal site most frequently occupied by aminoacyl-tRNA. The aminoacyl-tRNA in the A-site functions as the acceptor for the growing protein during peptide bond formation.P-site: the ribosomal site most frequently occupied by peptidyl-tRNA, i.e. the tRNA carrying the growing peptide chain. The P-site is also referred to as the puromycin-sensitive site. Puromycin is an antibiotic which shows similarities with a part of aminoacyl-tRNA. When puromycin is present in the A-site, the peptide can be linked to puromycin via a peptide bond. Thus, peptidyl-tRNA in the P-site is located in the puromycin-sensitive site. E-site: the ribosomal site harboring deacylated tRNA on transit out from the ribosome.

The aim of this experiment was to explore the wide variety of organisms found in biofilms that form on toothbrushes. My lab partner’s used toothbrush was the source of these bacteria, and was sacrificed for the purposes of this experiment. The toothbrush head was cut off and placed into sterile saline to create a fluid suspension. An inoculum from the toothbrush-saline suspension was streaked onto TSA, SBA, MacConkey agar (MAC), Mitis-Salivarius agar, and CDC anaerobe blood agar plates. After incubating the plates, it was expected that each one would contain several different colonies that would allow the bacteria growing on the toothbrush to be directly observed.

The results of this experiment were in accordance with my expected results. On the slide culture of P. aeruginosa, a thick, slimy, green goo had grown and covered the entire slide and surrounding glass dish. When I attempted to remove the glass slide from the dish, long thick strands of biofilm formed between the slide and the glass dish. It was like when you take a bite of cheese pizza and the cheese forms a long, gooey strand between your mouth and the slice. When I put the P. aeruginosa slide under the microscope at 400x, I could see long, thin, greenish grey strands of biofilm going in all different directions. It was clear from this slide that P. aeruginosa formed a biofilm that contained lots of EPS. At 1000x the strands were not as defined, but rod shaped bacteria with thin EPS and biofilm filaments in the extracellular space were clearly visible. This showed that P. aeruginosa is an excellent biofilm former, and can form biofilms in an artificial environment in the lab.