Sordaria Finicola Lab Report

The following tests according to the lab manual were performed: gram stain, fermentation tubes, methyl red, vogues proskauer, sulfur, indole, motility and growing it up on MacConkey agar. The gram stain was performed incorrectly the first time. This is because the decolorizer was not on the bacterium slide for long enough, giving a false outcome.

C-Fern plants are a strain of Ceratopteris richardii and have a rapid reproductive cycle, making them perfect subjects in lab to be tested and observed on population genetics. Population genetics is the study of genetic variation and allelic frequencies on a specific group over an amount of time. It is a great way to predict future genetic information on more than just the C-Ferns. In this experiment, two different generations for gametophytes and sporophytes of C-Ferns were observed and counted for the amount of wild type and polka dot mutant individuals within a sample and a population. The overall results demonstrated a 1:1 ratio of mutant to wild type in the F1 gametophyte generation for both the sample and population, which was expected. The F1 sporophyte generation demonstrated a 1:1 ratio of mutant to wild type in the sample and a 2:1 ratio of mutant to wild type in the population. A 3:1 ratio of mutant to wild type was expected in the sporophytes. It was concluded that the polka dot mutant is recessive in sporophytes and demonstrates random fertilization in the diploid stage, but not in gametophytes. This process of population genetics in C-Ferns can be extremely beneficial in other organisms, such as humans. Population genetics could be a tool in medicine in determining human

The purpose of this experiment is to determine which stimuli sowbugs prefer more, moist or dark. However, to confirm that sowbugs prefer dark and moist environments we had to create an experiment to prove this. We proved sowbugs prefer dark environments by using a lamp to create a light environment and cardboard over half the petri dish to create the dark environment; the sowbugs chose the dark side. Then we proved sowbugs preferred moist environments over dry ones by creating a wet environment on one side and a dry environment on the other side of the petri dish. After our final experiment, we were able to determine that sowbugs prefer the dark stimuli over moist stimuli.

Meiosis consists of one DNA replication and two nuclear divisions resulting in 4 daughter cells. The process which provides for genetic variation is crossing over. Crossing over occurs in the early stages when homologous chromosomes move together so that their chromatids form a tetrad. This is called synapsis and allows for the exchange of chromosome sections.

The combinations of 4:4, 2:2:2:2, and 2:4:2 can arise through crossing-over (Burpee et al., 2015). A 2:2:2:2 and 2:4:2 combination indicates crossing-over while 4:4 signifies the recombination did not occur. This process occurs during prophase I of meiosis between Wild Type and Tan isolates crossing-over (Burpee et al., 2015). It was initially thought that recombination was random; however, research from the Evolution Canyons shows that S. fimicola is, indeed, affected by the environment (Burpee et al., 2015). This could possibly be from radiation; however, research in this area is sparse. Certain species of fungi have shown increased resistance to radiation (Saleh, Mayo, & Ahearn, 1988), but studies on S. fimicola have not been documented. Based on this information, I hypothesize that when S. fimicola isolates are exposed to X-ray radiation the crossing-over frequency will increase. To test this theory one Tan and one Wild Type sample (with different combinations of x-ray radiation) was placed in a petri dish diagonal from each other. This was repeated to create four quadrants. The S. fimicola isolates were incubated for two weeks to produce perithecia (Burpee et al.,

After precisely conducting the experiment and tabulating the results, data for Paraquat toxicity upon P. vulgaris plants can be interpreted over several different parameters. The parameters by which Paraquat toxicity was examined within this experiment involve visual observations, x-ray diffraction, chlorophyll concentrations, protein concentrations, and lastly malondialdehyde (MDA) concentrations on a per mg of protein basis. As stated before Paraquat is very widely used herbicide known to produce superoxide anions leading to chloroplast membrane damage and ultimately a variety of adverse effects upon the host organism, in this case P. vulgaris (Chia et al., 1982).

2) Record the shape of the bacteria, the arrangement of the bacteria, and the gram staining characteristics.

Define the term crossing over. (3 points) During meiosis’ prophase the homologous chromatids exchange segments.

Citrobacter Freundii is a species of bacteria that can be potentially harmful to humans. It is known to cause meningitis by protruding into the brain and replicating itself (1). The Citrobacter species has also been found as a cause of some urinary tract infections, diarrhea, and even gastrointestinal diseases and symptoms (3). C. Freundii can be located in a wide variety of soils and water (3). Lastly, it is also the cause of many nosocomial infections due to its presence in water (1).

In this lab, the organism that we have been working with is the bacterium, Serratia marcescens. S. marcescens is a member of the Enterobacteriaceae family, and tends to grow in damp environments. S. marcescens is an ideal bacterium to work with in the lab because it reproduces quicker than other bacterium. This bacterium produces a special pigment called prodigiosin, which is red in color. The prodigiosin pigment is intensified when S. marcescens is grown at higher densities. During our experiment, temperature, pH, salinity concentration and oxygen requirements were tested on S. marcescens to measure their optimal growth and prodigiosin production.

Part B: Genes X, Y, and Z are linked. Crossover gametes between genes X and Y are observed

16. Stack your group’s set of plates on top of one another and tape them together. The plates should be left upright position to allow the cell suspension to be absorbed by the agar.

Abstract: This experiment was exploring our curiosity of sowbugs and their preferences. Our main question was about how the sowbugs natural diet can affect their preference for sodium chloride also known as table salt and glucose which is also known as sugar. The experiment involved testing how much time each sowbug spent in each substance when in a tray with both salt and sugar on opposite sides.

In the world of microbiology it is vitally important to be able to discern the identities of microorganisms. Not only is it important in a lab setting but as well as in healthcare in general. Properly identify what strain of bacteria a person has will aid in the proper medicine and dose given. Throughout the semester we have learned about different types of bacteria and certain test that can clearly identify them. The purpose of this lab report is to identify a Gram-positive or Gram-negative bacterium. Using all the knowledge of procedures and lab techniques identify the unknown and discuss all the tests you performed.

In this lab experiment, students had to create a growth curve for E. coli. The E. coli growth curve would illustrate the progression of the population of E. coli a set time period. In this case, the growth curve depicted the population of E. coli over a 12-hour period. The growth curve for E. coli was created from the absorbance levels, the optical density(OD), recorded from the spectrophotometer.