Recombination Frequency In Sordaria

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.

The purpose of this experiment was to measure the T4 reversion rate to wild type combination, and the recombination frequency recombination frequency of the T4 mutants to the wild type. Also to determine the distance between the two mutants, which are T4 rII 29 and T4 rII 31.

Many tests were completed on the unknown such as gram staining and inspection under microscopes to find whether the bacterium is gram positive or gram negative. Chemical resistance tests were also performed to see if certain chemicals affected the unknown growth or if it didn’t affect the bacteria at all. Each biochemical test

Prior the conduction of this experiment, Sordaria of different ascus types (WT and T) were exposed to significant levels of radiation. There were three experimental groups for this experiment and crosses accordingly. Crosses were set up in containers by placing different Sordaria groups in alternating fourths of the mating agar. The Sordaria naturally grew outwards to the different adjacent Sordaria groups and inter-mated through meiosis. This provided a variety of different crosses throughout each experimental group. The squashes were prepared by obtaining a clear slide and placing a small amount of water in order to trap and spread out the perithecia. Once the individual perithecia were separated, they were busted by applying slight pressure with an eraser head, but done carefully enough not to pop the individual sacs. Frequencies were calculated by counting the number of

Apply your understanding of how alleles assort and combine during reproduction to evaluate a scenario involving a monohybrid cross.

Part A: Two genes that are separated by 10 map units show a recombination percentage of

After the incubation period the bacteria was observed for pure colonies. The colonies were sampled and the three streak plate technique was repeated and this sample was incubated for forty eight hours at 37 degrees Celsius. After the incubation of the colonies, a gram stain was performed which is defined in the lab manual.

The wild type (WT) and most common color is black, while the mutant type (T) is a lighter tan spore. Each spore must be carefully analyzed along a chain of eight to accurately determine if cross-over played a role in the creation of the ascus. Three different forms of ascus are possible through sexual reproduction of separate hyphae. The different forms are caused by chromosomal cross-over when homologous pairs attach during Prophase I of meiosis. An ascus showing a 4:4 ration of WT to T spores represents an ascus that did not undergo any cross-over. There are two different patterns of cross-over found in Sordaria with the ratios of 2:2:2:2 and 2:4:2 (WT to T spores or vice versa). The different ratios are determined by which sister chromatid that genetic information was crossed over, the ends of the chromosomes being the most

Research groups from the Imperial College of Science, Technology and Medicine and the Institute of Evolution at the University of Haifa have been studying the model organism, Sordaria fimicola, in regards to controlling cross over frequency in response to environmental pressures. Sordaria fimicola is a good model organism because it has a fast life cycle and elongated asci that are easily seen under a microscope. In addition, there are multiple different combinations of ascospore colors due to recombination during meiosis.

There was no difference between the control plates which proves that the lid on the plate serves as significant protection, potentially shielding the bacteria to the mutagenic effects the UV light. All three plates were incubated at 25 degree Celsius. The first Control plate showed lots of red and furry growth and the original pattern of swiping was observed in all the quadrants. The second control plate was also observed to have furry and pigmented red growth in all the quadrants, despite being exposed to UV light due to the plate lid during exposure. The experiment plate showed the most interesting results, in the 10 second UV exposure quadrant the bacteria had red pigmented growth but it is speckled, pinpointed and the original swipes were not observed. Moreover the growth seemed not as furry and robust as the control plates. The quadrant exposed to 20 sec of UV light showed significantly less growth than the 10 sec quadrant and the colonies are pinpointed with several beige colonies in between the red speckles. Original swipe pattern of the bacteria was not observed in this colony. In the quadrant exposed to 30 seconds of UV light, the differences are even more significant as the colonies are few and far in between and only several pinpoint red colonies found with a few beige colonies and some colonies with red centers surrounded by beige. The effects of UV light are very drastic in the 40 second quadrant as the growth is severely diminished with only a

There were eight different phenotypes among the progeny. The highest phenotypic frequency was the w+m+f+ at 40% of the progeny. The lowest was the w+mf+ with only 2 % of the progeny (Table 3). The sum of the recombinant frequencies between genes, table 4, was used to determine the gene distance. The recombinant frequency was determined by counting the number of individuals whose genes differed from that of the parental type. For example, how many individuals white eye gene, and miniature wing gene, differed from both wild-type or both mutants. Recombination occurred between the white and miniature gene 33 times. Recombination occurred between the miniature and the forked genes 31 times. Recombination occurred between the white and forked genes 44 time. Double recombination occurred 10 times. Therefore, genes w and f are 64 m.u. apart, m and w are 33 m.u. apart, and m and f are 31 m.u. apart (Figure

Making the onion tip root cell slide was successful. Our results supported the hypothesis because we saw cells in the onion root tip in prophase, metaphase, and anaphase. As we went up in power objectives, each phase of the cell became more definitive. The cell root was a great indicator of the structures of the different cycles of the cell. This is important because we will be prepared for future labs working with the microscopes and can now adjust it for the best view of the slide. We practiced working with the compound light microscopes and different phases of the cell cycle. Onion root tips are useful to observe mitosis because the cells are frequently diving as the root grows. So when we stained the cell, we caught many cells in different phases. The significance of this lab was to better understand the process and stages of mitosis and meiosis and compare and contrast the mitotic process in plants and animals. We grasped the concepts of what the chromosomes look like, and what they look like in each step of the processes. Having read much about mitosis and meiosis, seeing these cells was the real application of describing and understanding the stages.

perfringens which causes the lysis of erythrocytes (Harris, Sims, & Tweten, 1991). C. perfringens is also a spore forming bacteria, allowing it to survive in very hostile conditions that other bacteria would die in; C. perfringens can survive moist heat and UV radiation (Carlisle, 2014). The transmission of C. perfringens is not community based, meaning that it is not transferred from person to person; rather, it is transmitted by contamination of deep wounds – because these tissues provide the anaerobic environment needed for C. perfringens to survive – by anything, most commonly dirt, that contains C. perfringens (The Public Health Agency of Canada, 2011). The incubation period for C. perfringens can vary anywhere between six and twenty-four hours. The most common incubation period is between ten and twelve hours (“Clostridium Perfringens”,

B. pertussis is a very small Gram-negative aerobic coccobacillus that appears singly or in pairs. Its metabolism is respiratory, never fermentative, and taxonomically, Bordetella is placed among the "Gram-negative Aerobic Rods and Cocci" in Bergey's Manual (Todar, 2008). Bordetella is not assigned to any family. The bacteria are nutritionally concerned and is usually formed in rich media filled with blood. B. pertussis produces multiple antigenic and biologically active products, including pertussis toxin, filamentous hemagglutinin, agglutinogens, adenylate cyclase, pertactin, and tracheal cytotoxin (C, 2015). These products are responsible for the features of pertussis, and an immune response to one or more would produce immunity after the infection. Although however the immunity following the pertussis infection does not appear to be permanent. Some means of infections would be through airborne droplets, respiratory secretions and droplets. It occurs less frequently by contact with newly contaminated articles of an infected

In order to obtain well-isolated discrete colonies, the quadrant streak and spread technique was used. This allowed dilution of the original microbial material over the entire surface of the plate. As the original sample was diluted by streaking and spreading it, over successive quadrants the number of organism decreases. Usually by the third or fourth quadrant only a few organism were transferred on the by the inoculating loop and theses produce a few isolated