Tuesday, March 24, 2020

Identification of Fungi free essay sample

While the identification of bacteria relies heavily on biochemical testing, the identification of molds tends to focus on their structural features. You will examine the appearance of growing cultures of several different molds and then prepare wet mounts of each to examine microscopically. Your instructor will provide you with a ‘key’ which includes information regarding some of the more common molds. You will use this key to identify the lab isolates. You will also prepare wet mounts of a yeast culture and use the ocular micrometer of your microscope to measure these cells for comparison to bacterial cells. Part A: Molds Method: 1. Obtain an agar plate culture of an ‘unknown’ mold. All molds have been cultured on Sabouraud’s dextrose agar (SDA). 2. Visually examine the culture. A dissecting (or stereo-) microscope may be useful for this purpose. Record:a. colour or pigmentation of the culture b. texture (powdery, viscous, etc. ) 3. Obtain a clean microscope slide and add 1-2 drops of lactophenol cotton blue (stain) to it. We will write a custom essay sample on Identification of Fungi or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page 4. Obtain a short piece of cellophane tape. Be careful to touch it only at the two ends. 5. Press the ‘sticky side’ down onto the surface of the mold culture. If there are different colours present in the culture, try to ‘pick up’ a portion of each. Spores may be a different colour than the mycelia – usually darker. Remember that you want to keep the reproductive structure (the part of the mold where the spores are located) intact. 6. Place the tape ‘sticky side’ down onto the drop of lactophenol cotton blue on the microscope slide prepared in Step 3. Try to keep the tape smooth; avoid ‘wrinkles’ or folds if possible. 7. Examine the slide using the light microscope. Start by using low and medium power to locate the reproductive structures. Higher magnifications may then be used for more detailed observations. 8. Draw a diagram of the mold structure. Are the mycelia septate or non-septate? Record the stain and magnification used. 9. Consult the key provide by your instructor. Identify the possible genus (or genera) for each of the provided unknowns. Part B: Yeast Method: 1. Obtain a broth culture of Saccharomyces cerevisiae (baker’s yeast). 2. Add a few drops of this culture to a clean microscope slide together with a drop or two of the lactophenol cotton blue dye. Place a cover slip over the preparation. . Examine the yeast cells using the light microscope. Can you see any budding cells? 4. Draw a diagram to illustrate the structure of a typical yeast cell. 5. Use the ocular micrometer to estimate the size of the yeast cells. Assume that the length of one ocular division is approximately 2. 5 ? m for the 40x lens and approximately 1. 0 ? m for the 100x (oil immersion) lens. Note that yeast cells are oval; as suc h, the length and width (diameter) must both be determined. Take the average of three cells. Complete the provided worksheet

Friday, March 6, 2020

Boradinging the view of the Bl essays

Boradinging the view of the Bl essays It seems that it may be mass media or pop culture that seems to portray talking black cool. Karla D. Scott from Saint Louis University makes the point that many people in main- stream America have the, perception that black language use also indicates stupidity on the part of the user. (Gonzalez, 183) Although it is not necessarily true, it seems like if you are a African-American, and you do not use slang or ebonics you are considered a sell out or that you, you do not sound black. Ebonics which was introduced in Oakland, California in 1996, is the term used, ...in reference to language of black Americans.( Gonzalez, 183) Many images that come to mind when discussing or trying to understand the black language may come from some icons in American pop culture, like Buckwheat from the Little Rascals, which shows a young black boy, who speaks incorrect English and seems to somewhat uneducated (Gonzalez, 184-85). This is a common theme in many television shows and movies and it is quite unfortunate that many outside the black culture and even in its own culture feel that all blacks speak this way and that is simply not true. Whereas those African-Americans who are educated and do speak proper English, are considered other blacks and maybe considered to be a sell out. Overall, unless you are an African American, it is awfully hard to comment on this issue. If you are not part of a culture it is unfair to make a strong statement whether you agree or disagree with a particular aspect of the issue. But I think that Bill Cosby this past summer said it best, that he feels strongly that young blacks are not going to be successful or make it in this world if they keep acting the way they do. What he meant is that what see in the music videos is not reality; you cannot be a thug and act like a punk and expect to make it in this world. And I fe ...