Plantae and Fungi: Transect Biodiversity, July 9th, 2015
Introduction: The purpose of this experiment was to understand the differing traits present in the plethora of plants that exist and to understand the significant role that fungi play in our daily lives. Both plants and fungi are eukaryotes, however plants are autotrophs, giving them the ability to photosynthesize, while fungi are decomposers, allowing them to release enzymes that break down organic materials to absorb. I hypothesized that there would be diversity evident in the vascular systems, specialized structures, and mechanisms of reproduction in the plants and fungi found in our transect.
Methods: A leaf litter sample from our transect was collected and stored in a Ziploc bag. Additionally, five different plants were obtained from the area. To prepare for the Berlese Funnel, 25 mL of 50:50 Ethanol/water solution was poured into a 50 mL tube. Then the test tube was attached to the bottom of a funnel as the funnel was placed on a ring stand. Screening material was inside the funnel that allow filtration of the leaf litter sample after it was placed in the funnel. The ring stand was then placed under a light.
Results: 1) Lady fern was found by the left side of the tree in our transect. There were about 10. There were green leaves, a red stem, and it varied in length between 1 and 2 feet. The plant is vascular and some of its specialized structures include rhizomes and spores. The spores grow underneath the leaves and is not monocot or dicot. 2) The english ivy was found by the left side of the river and there were between 3 and 4 found. The leaves were dark green and stem was long and brown. Specialized structures include aerial roots, but no flowers were evident. The plant is dicot and spread by seeds with a hard outer shell. 3) The flowering dogwood was found to the right of the river. There was only one of these trees. It was about twenty feet tall and there were no flowers yet. The tree was vascular and its leaves were opposite and ovate. The tree had dicot seeds and its seeds are spread by fruit. 4) The royal standard hosta was found across the water behind the flowering dogwood tree. There were about 10 of these plants. The plant was vascular and its leaves were large and round but there were no flowers. Specialized structures include rhizomes and stolons. The plant is monocot and the seeds are found within the flower. 5) The swamp saw grass was right next to the stream on the amphitheater side. There were about 15 of these plants. This plant had tall, thin blades of green grass. It is vascular and its specialized structures also include rhizomes and like the royal standard hosta, it is monocot.
Discussion: There was variation in the plants that we discovered confirming the biodiversity evident in our transect. The five plants collected all appeared to be vascular. However, there were no fungi identified.
Microbiology and Identifying Bacteria with DNA Sequences: Bacterial Growth on Plates, July 7th, 2015
Introduction: Bacteria are prokaryotes and are considered one of the three domains of life. There is often a notion that bacteria largely play a negative role in our lives, but there is only a very small amount of bacteria in our bodies that are actually pathogenic- the rest are neutral or serve beneficial purposes. The purpose of the experiment was to witness firsthand the differences in morphology of various bacteria and observe their ability to be antibiotic resistant. Additionally, another goal of this experiment was to identify bacteria using PCR and DNA sequencing techniques. If nutrient agar was on the plate, then I expected that there would be more bacterial growth on the plate because the nutrient agar would provide nourishment for the bacteria. If tetracycline was on the plate, then I expected that there would less bacterial growth on the plate because the tetracycline is an antibiotic. However, it was possible that there would not have been a significant reduction in bacterial growth on the plates with tetracycline if the bacteria happened to be antibiotic resistant.
Methods: Firstly, the bacterial growth on the eight plates was observed and recorded to compare the differences in numbers between the plates with nutrient agar and the plates with tetracycline. Then a wet mount slide was prepared of two distinct colonies from both types of plates and the colonies were described. To prepare the wet mount, a sterilized loop was used to pluck a very miniscule amount of bacteria from the plates. Then the selected bacteria was mixed with a drop of water on the wet mount slide. The shapes of the cells from the bacteria and their motility was observed through 10x and 40x lenses. Then to begin the gram stain, the wet mount slide was fixed by passing it over the flame of a Bunsen burner. The four wet mount slides were placed on a staining tray and drizzled with crystal violet for a minute. Then it was rinsed with a wash bottle. Again, the process was repeated with Gram’s iodine mordant. Then the slides were washed with 95% alcohol for 10-20 seconds for decolorization to occur. Lastly, safranin was drizzled for 20-30 seconds over the slides and rinsed off. Kimwipes were used to remove excess water from the slides before they were observed under the 40x. Lastly, 10^-5 plate with tetracycline and 10^-9 plate with nutrient agar were chosen for the PCR reaction. We extracted a bacterial colony from each and added primer with a PCR bead before leaving the tubes in the PCR machine.
Discussion: After checking on the Hay Infusion culture, there appeared to have been some changes in its appearance and smell. The culture was more clear, less foggy, however there was development in the amount of film that was on the surface. There was still dirt settled at the bottom, except now with the addition of white chunks floating in the water. The odor was more powerful and still very swamp-like. The appearance may change from week to week because of the diminishing sources of nutrients in the jar to sustain the life inside of it. The results of the plates were different from what we had anticipated. The plates with tetracycline had more bacterial growth than the plates with nutrient agar likely because of the presence of an antibiotic resistant gene in the transect.
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