Microbiology Lab Test 1 – Flashcards
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| Exercise 1.1 Name the parts of a microscope and state the function of each. |
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| Base - Support for microscope Substage light - Illumination source located on base of microscope which shines light up through the condenser to the slide and object being viewed Stage - platform that supports slides for viewing Mechanical stage and control knobs - Apparatus which holds slides in place and which is used to adjust the (X and Y) position of the slide on the stage Condenser - Substage lens that focuses the light on the specimen so that each of its points are evenly illuminated Condenser knob - used to adjust the condenser up and down Iris diaphragm lever - Opens and closes the condenser, thus regulating the amount of light shining through the condenser onto the object. Helps control contrast on the specimen Coarse adjustment knob - Used with lower power objective lens to bring an object roughly in focus Fine adjustment knob - used for fine focusing of all objective lenses Head - Supports the ocular and objective lenses Arm - Portion of microscope connecting the head and base Ocular or eyepiece - Lens closest to the eye which magnifies the image produced by the objective lens Rotating nosepiece (turret)- Structure on the head that holds all the objective lenses and which may be rotated to change from one lens to another Objective lenses - lens closest to the specimen which magnifies the specimen Scanning power - Generally about 4x magnification Low power - generally about 10x magnification High power - generally about 40x magnification Oil immersion lens - Generally about 100x magnification and utilizes oil so that a more highly magnified and sharper image may be obtained Rheostat - Used to vary the intensity of light |
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| Exercise 1.2 What are the total magnifications obtained with each objective lens? |
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| 1,000, 100, 450 |
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| Exercise 1.3 What is the resolution of this type of microscope? |
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| 0.2um |
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| Exercise 1.4 Why is blue light used when possible? |
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| Because blue light has the shortest wavelength of all visible light and resolution is inversely proportional to wavelength of light |
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| Exercise 1.5 What is the proper method to carry a microscope? |
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| With two hands. One hand holds the base and the other is on the arm of the microscope |
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| Exercise 1.6 What has to be used with every 100x objective lens? Why? |
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| Immersion oil because it increases the numerical aperture of the objective lens and prevents wide angles of light from being refracted away from the lens |
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| Exercise 1.7 This scope is parfocal. What does that mean? |
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| Once focused with a low power objective, the image remains always in focus for the other objective lenses, or very nearly in focus. This makes finding your specimen at high power much easier |
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| Exercise 1.8 Which objective lens has the smallest working distance? |
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| 100x |
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| Exercise 1.9 What are the three basic bacterial shapes? |
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| Bacilli (rod), cocci (spherical), spiral (helical) |
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| Exercise 1.10 What is always done to a microscope after using the 100x objective lens before it is put away in the cabinet? |
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| Clean off the oil from the lens |
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| Exercise 2.1 Will the media prepared from this powder be a liquid or solid media? How do you know (besides looking at the name of the medium)? |
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| Solid. Look at the list of ingredients and look for the solidifying agent, agar |
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| Exercise 2.2 How should this medium be sterilized prior to its use? |
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| Autoclave at 15psi for 15 min, at 121 degrees C |
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| Exercise 2.3 To make up 500 ml of this media, how much of the following would you needa)water b)Dehydrated media |
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| a)500 ml b)20 g |
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| Exercise 2.4 What percentage of casein will be in the final medium? |
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| 1.5% casein (15 grams in 1000 ml is like 1.5 in 100 ml, which would be 1.5%) |
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| Exercise 3.1 Be sure you know the basic aseptic microbiological transfer techniques you learned in Exercise 3 |
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| See Exercise 3 for specific details; review the proper techniques and sequences for transferring organisms from one type of media to another |
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| Exercise 3.2 If you wanted to isolate single colonies from a mixed culture, what type of culture would you use (e.g. streak plate, agar slant, broth)? |
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| Streak plate method (isolated colonies on an agar plate) |
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| Exercise 3.3 If you wanted to keep a pure culture of bacterium for a long time (weeks or a couple of months), what type of culture would you use (streak plate, agar slant, or broth)? |
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| An agar slant |
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| Exercise 4.1.1 What reagents did you use (and in what order) for each of the following stainsa)Gram stain (Lab 4) b)Schaffer-Fulton Endospore stain (Lab 8) c)Capsule stain (Lab 11) |
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| a) Crystal Violet, Iodine, Ethanol, Safranin b)Malachite Green, Safranin c)Capsule stain: 1)Mix equal amounts of India ink and water on glass slide, then add a loop of culture. Gently stir and spread mixture. 2)Allow smear to dry without heat fixation 3)Counterstain with methylene blue for 3 minutes 4)Rinse the slide very carefully and dry 5)Oil immersion. Blue cells w/ clear capsules on a black background |
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| Exercise 4.1.2 What is the function of each of the reagents for these stains |
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| a)Gram Stain Crystal violet - Primary stain Iodine - Mordant (fixes stain) Ethanol - Decolorizer Safranin - Counterstain b)Schaffer-Fulton Endospore Stain Malachite Green - Primary stain Safranin - Counterstain c)Capsule stain India ink - stain Methylene blue - counterstain |
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| Exercise 4.1.3 What procedure is used to apply and fix a bacterial smear for staining? |
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| Bacterial smears are prepared by placing a drop of broth culture on a clean microscope slide and spreading it in a circular motion. The smear is allowed to air dry and fixed by lightly passing it through the flame. If a smear is made from bacterial growth on an agar surface, a small drop of water is first placed on the slide and a very small amount of bacterial growth is emulsified in the drop to make a lightly turbid smear. It is also dried and fixed by flaming. |
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| Exercise 4.1.4 What about the bacterial cell is responsible for the characteristic response of a cell wall to the Gram stain? |
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| Gram Stain - The Gram stain reaction is dependent upon the nature of the cell wall of the bacterium. The Gram positive bacteria have a thick layer of peptidoglycan, which is able to hold the crystal violet-iodine complex within the cell wall when alcohol is applied. The Gram negative cell wall has only a thin layer of peptidoglycan with a lipid membrane around it. When the alcohol is applied it is not thick enough to hold the crystal violet-iodine complex. |
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| Exercise 4.2.1 Describe the arrangement of flagella on the bacterium shown in the figure below: [image] |
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| Peritrichous - Many randomly all over (non-polar) |
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| Exercise 4.2.2 Can you name and describe the other types of flagellar arrangements? |
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| Flagella Arrangements: a)Monotrichous - Single flagella at one end (polar) b)Lophotrichous - Many from one end (polar) c)Amphitrichous - One or more at each end (bi-polar) d) Peritrichous - Many randomly all over (non-polar) |
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| Exercise 4.3.1 What does the clear zone represent in this India ink preparation[image] |
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| Capsule |
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| Exercise 4.3.2 [image] What is the function? |
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| Protection against phagocytosis (inside the body) and dehydration (outside the body) |
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| Exercise 4.3.3 [image] What two pneumonia-causing bacteria are noted for their large capsules? |
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| Streptococcus pneumonia and Klebsiella pneumoniae |
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| Exercise 4.3.4 [image] Which one of the two would this one be? support your answer |
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| This one would be Klebsiella pneumoniae because Klebsiella is a bacillus and Streptococcus is a coccus |
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| Exercise 5.1.1 [image] What fungus produced this special type of spore a)What is the function of fungal spores b)How does this function differ from the primary function of bacterial endospores? |
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| Histoplasma capsulatum a)Spores of fungi are primarily used by these microbes for reproduction. One mold can produce millions of spores, each of which can produce a new fungus colony. The spores also serve for dispersal and survival in dry situations. b)The function of fungal spores contrasts with that of bacterial endospores whose essential function is for survival in unfavorable environments. Bacterial endospores are not used for reproduction/increases in number. One cell can only produce one endospore that germinate into one bacterial cell |
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| Exercise 5.1.2 [image] Name the disease cause by this fungus |
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| Histoplasmosis |
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| Exercise 5.1.3 [image] At what temperature would the fungus have to grow to produce these spores? |
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| 25 degrees Celsius |
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| Exercise 5.1.4 [image] What is the phase of growth called? |
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| Mold |
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| Exercise 5.1.5 [image] What is the specific name given to this spore type? |
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| Tuberculated chlamydospore |
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| Exercise 5.1.6 [image] In what part of the country is this fungus found? |
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| U.S.A. (Eastern) Ohio and Mississippi River Valleys |
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| Exercise 5.1.7 [image] How does one acquire this fungus infection? |
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| Inhalation of the infectious tuberculated chlamydospores |
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| Exercise 5.2.1 Look at the photo provided with this station ("Histoplasma capsulatum" page on fb) and notice the large, encapsulated yeast cells. Name the following: a)Disease b)Fungus c)Phase of growth |
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| a)Cryptococcosis b)Cryptococcus neoformans c)Yeast phase |
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| Exercise 5.3 These are opportunistic yeast cells [image] 1)What genus and species would be seen in this slide2)What disease could these cells cause3)How do yeast reproduce? |
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| 1)Candida albicans 2)Thrush, vaginitis, cutaneous candidiasis 3)Budding from mother cell |
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| Exercise 5.4.1 What type of organism is this? What is the name of this organism[image] |
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| This is a fungus known as Aspergillus |
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| Exercise 5.4.2 Is this organism a human pathogen[image] |
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| Aspergillus is an opportunistic pathogen of humans causing primarily respiratory tract infections (Aspergillosis) |
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| Exercise 5.4.3 What is the name of the toxin produced by this organism[image] |
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| Aflatoxin |
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| Exercise 5.4.4 What are some of the complications of this toxin[image] |
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| Can cause acute necrosis and cirrhosis of the liver leading to liver cancer |
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| Exercise 6.1.1 This is a tube of semisolid motility medium: [image] a)If there are two tubes displayed, which of the two tubes contains the motile bacteriab)If there is only one tube displayed, are the bacteria in this tube motile? How can you tell? |
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| a) The motile bacteria would be in the tube where there is turbidity extending from the center inoculation stab. The one with the bacteria growing only down the center in the inoculation stab is the non-motile bacteria b) No, one can tell because turbidity has not spread from the center stab line. Non-motile bacteria grow only along the stab and do not "swim" out from it to make the surrounding media turbid. |
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| Exercise 6.1.2 [image] What other techniques can be used to determine bacterial motility? |
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| Flagella stain, hanging drop slide |
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| Exercise 6.1.3 [image] By what means are most bacteria motile? |
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| Flagella |
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| Exercise 6.1.4 [image] What organelles are used by spirochetes for motility? |
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| Axial filaments |
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| Exercise 6.2.1 What is this slide called[image] |
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| Concave or concavity slide |
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| Exercise 6.2.2 What is it used for[image] |
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| Motility observations using hanging drop preparations |
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| Exercise 6.2.3 What other techniques are used to demonstrate the same thing[image] |
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| Flagella stain, semisolid motility medium |
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| Exercise 7.1.1 Does ordinary hand washing remove all bacteria from the skin? Does a surgical scrub? |
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| Ordinary hand washing does not remove all bacteria from the skin neither does a surgical scrub. |
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| Exercise 7.1.2 Explain why hand washing is still done to prevent the transmission of disease |
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| To remove transient microbes (bacteria, viruses, fungi, etc.) that could be pathogenic and to reduce the contamination level of the skin |
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| Exercise 7.2.1 If surgical scrubbing does not remove all the microbes, why do a surgical scrub? |
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| See experiment 7 |
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| Exercise 7.2.2 What type of medium is blood agar? |
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| Enriched medium. It is also differential media because it allows one to determine the hemolytic patterns |
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| Exercise 7.2.3 Acquiring an infection from the rim of a drinking glass would be an example of transmission via a/an... |
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| Fomite |
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| Exercise 8.1.1 What stain(s)/ staining procedure was used on this slide[image] |
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| Schaffer-Fulton Endospore stain |
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| Exercise 8.1.2 [image] What genus of bacterium are these? What disease does this genus cause? |
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| Bacillus, anthrax (or Clostridium, gas gangrene, tetanus, botulism, pseudomembranous colitis) |
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| Exercise 8.1.3 What is the function of the green structures[image] |
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| The green structures are the bacterial endospores, used as a survival strategy during harsh conditions/lack of nutrients/lack of water |
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| Exercise 8.1.4 What special procedure has to be followed to stain the spores[image] |
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| Heating for 4 minutes in the presence of Malachite green stain |
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| Exercise 8.1.5 What dye in the stain was taken up by the following[image] a)Vegetative cells b)Endospore |
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| Dye components take up by different parts: a)Safranin b)Malachite green |
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| Exercise 8.2.1 These bacteria (reddish bacilli) and tissue were taken from a diseased cow. Upon growth in the laboratory, endospores were formed [image] Name the disease that most likely killed this cow. |
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| Anthrax |
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| Exercise 8.2.2 These bacteria (reddish bacilli) and tissue were taken from a diseased cow. Upon growth in the laboratory, endospores were formed [image] What bacteria caused this disease? |
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| Bacillus anthracis |
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| Exercise 8.3.1 [image] Name this apparatus |
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| Anaerobic jar (chamber) |
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| Exercise 8.3.2 [image] What is its function? |
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| To provide anaerobic conditions for bacteria that require this type of atmospheric environment |
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| Exercise 8.3.3 What bacterial genus we studied this semester is grown in this type of apparatus[image] |
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| Clostridium |
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| Exercise 8.3.4 What diseases are caused by these bacteria (Clostridium)? |
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| Gas gangrene, tetanus, botulism |
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| Exercise 8.3.5 What other techniques are used to provide anaerobic conditions? |
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| Cooked meat medium, thioglycollate medium, anaerobic incubator |
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| Exercise 8.3.6 Can a candle jar be used? Why or why not? What is it used for? |
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| No, a candle jar cannot be used because the candle goes out before all the oxygen is burned up. Candle jars are used to provide an atmosphere with increased carbon dioxide for those bacteria such as Neisseria that grow better with it. |
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| Exercise 9.1.1 Review the Kinyoun Acid Fast Stain procedure |
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| Kinyoun Acid Fast Stain procedure: a)Flood air-dryed smear with Kinyoun Carbol Fuchsin for 5 min. b)Rinse with water c)Decolorize with Acidified alcohol d)Rinse with water e)Counterstain with Brilliant Green (or methylene blue) for 30 seconds f)Rinse with water, blot dry, observe under oil-immersion |
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| Exercise 9.1.2 What color do Acid fast cells appear after this staining procedure? |
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| Acid fast cells (mycobacteria) should appear red |
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| Exercise 9.1.3 What is the name of the "waxy" lipid in the cell walls of Mycobacteria? |
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| The walls of mycobacteria contain Mycolic Acid |
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| Exercise 9.1.4 Name at least two diseases caused by Mycobacterium |
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| Diseases: a)Tuberculosis caused by Mycobacterium tuberculosis b)Leprosy (Hansen's disease) caused by Mycobacterium leprae |
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| Exercise 10.1.1 Did regrigeration kill the bacteria in the experiment? How was this shown? |
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| No. When placed in the incubator after refrigeration the bacteria grew into colonies demonstrating that they were not killed but were merely inhibited from growing. |
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| Exercise 10.1.2 What term is used for a procedure that inhibits the growth of bacteria rather than killing them? |
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| The term bacteriostatic is used for inhibition of bacterial growth (microbiostatic would be used for any microbe, fungistatic for fungi, etc.) |
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| Exercise 10.1.3 Which of the two bacteria in this experiment was not killed by heating in the steam bath? Why? |
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| The Bacillus culture was able to grow after being exposed to 70C+ because it forms endospores that are resistant to temperatures this high. Vegetative cells cannot survive temperature this high |
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| Exercise 10.1.4 What term is used for a procedure that kills or destroys bacteria? |
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| The term bacteriocidal is used for procedures that destroy or kill bacteria (microbiocidal for microbes in general, virucidal for viruses, etc.) |
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| Exercise 10.1.5 Which of the bacteria were killed by autoclaving? |
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| Both bacteria were killed by autoclaving. Autoclaving destroys all microorganisms |
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| Exercise 10.1.6 What is the normal time and temperature (and pressure if applicable) of the following methods of microbial controla)Autoclave b)Dry oven c)Boiling |
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| a)Autoclave - 121C, 15 mins, 15psi b)Dry oven - 160-170C, 120-180 mins c)Boiling - 100C, 15-20 mins |
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| Exercise 10.2.1 This is a photo of an antibiotic disk susceptibility test: [image] What is the formal name of this test? |
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| Kirby Bauer Disk susceptibility Test |
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| Exercise 10.2.2 This is a photo of an antibiotic disk susceptibility test [image] How would you determine if the bacteria cultured on these plates were susceptible to the antibiotics contained in the paper disks? |
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| Check the ones with the zones. To be accurate you would need a table of values to determine susceptible, intermediate, or resistant |
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| Exercise 10.2.3 This is a photo of an antibiotic disk susceptibility test [image] Why are some zones larger than others? Does a larger zone necessarily mean that the antibiotic is more effective? |
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| Because the size of the zone is inversely proportional to the size of the antibiotic molecule. Smaller molecules will diffuse faster and create larger zones of inhibition. Remember: One cannot compare the effectiveness of different antibiotics by their zones of inhibition in this test |
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| General Concepts 1 General Concepts from Selected Laboratory Exercises How were the following features of bacteria demonstrated in the laboratoryBacterial Capsules |
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| Exercise 11: Learned Gin's method of staining which consisted of India ink and Methylene blue stain |
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| General Concepts 2 General Concepts from Selected Laboratory Exercises How were the following features of bacteria demonstrated in the laboratoryBacterial motility |
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| Chapter 6: Learned how to do a hanging drop slide using a concavity slide |
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| General Concepts 3 General Concepts from Selected Laboratory Exercises How were the following features of bacteria demonstrated in the laboratoryResistance of bacteria to antibiotics |
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| General Concepts 4 General Concepts from Selected Laboratory Exercises How were the following features of bacteria demonstrated in the laboratoryDestruction of bacteria by autoclave and oven |
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| Chapter 10: |
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| General Concepts 5 General Concepts from Selected Laboratory Exercises How were the following features of bacteria demonstrated in the laboratoryEffectiveness of hand washing on hand disinfection |
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| Chapter 7 experiment 3: |
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| General Concepts 6 General Concepts from Selected Laboratory Exercises How were the following features of bacteria demonstrated in the laboratorySafety of cafeteria eating utensils |
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| Chapter 7 experiment 2: |
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| General Concepts 7 General Concepts from Selected Laboratory Exercises How were the following features of bacteria demonstrated in the laboratoryBacterial spores |
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| Exercise 1.1.1 Referring to a microscope, state the function of the base |
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| Support for microscope |
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| Exercise 1.1.2 Referring to a microscope, state the function of the substage light |
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| Illumination source located on base of microscope which shines light up through the condenser to the slide and object being viewed |
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| Exercise 1.1.3 Referring to a microscope, state the function of the stage |
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| Platform that supports the slide for viewing |
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| Exercise 1.1.4 Referring to a microscope, state the function of the mechanical stage and control knobs |
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| Apparatus which holds slides in place and which is used to adjust the (X and Y) position of the slide on the stage |
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| Exercise 1.1.5 Referring to a microscope, state the function of the condenser |
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| Substage lens that focuses the light on the specimen so that each of its points are evenly illuminated |
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| Exercise 1.1.6 Referring to a microscope, state the function of the condenser knob |
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| used to adjust the condenser up and down |
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| Exercise 1.1.7 Referring to a microscope, state the function of the iris diaphragm lever |
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| Opens and closes the condenser, thus regulating the amount of light shining through the condenser onto the object. Helps control contrast on the specimen |
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| Exercise 1.1.8 Referring to a microscope, state the function of the coarse adjustment knob |
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| Used with lower power objective lens to bring an object roughly in focus |
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| Exercise 1.1.9 Referring to a microscope, state the function of the fine adjustment knob |
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| used for fine focusing of all objective lenses |
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| Exercise 1.1.10 Referring to a microscope, state the function of the head |
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| Supports the ocular and objective lenses |
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| Exercise 1.1.11 Referring to a microscope, state the function of the arm |
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| portion of microscope connecting the head and base |
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| Exercise 1.1.12 Referring to a microscope, state the function of the ocular or eyepiece |
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| Lens closest to the eye which magnifies the image produced by the objective lens |
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| Exercise 1.1.13 Referring to a microscope, state the function of the rotating nosepiece (turret) |
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| Structure on the head that holds all the objective lenses and which may be rotated to change from one lens to the other |
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| Exercise 1.1.14 Referring to a microscope, state the function of the objective lens |
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| lens closest to the specimen which magnifies the specimen |
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| Exercise 1.1.15 Referring to a microscope, state the function of the scanning power |
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| Generally about 4x magnification |
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| Exercise 1.1.16 Referring to a microscope, state the function of the low power |
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| Generally about 10x magnification |
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| Exercise 1.1.17 Referring to a microscope, state the function of the high power |
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| Generally about 40x magnification |
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| Exercise 1.1.18 Referring to a microscope, state the function of the oil immersion lens |
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| Generally about 100x magnification and utilizes oil so that a more highly magnified and sharper image may be obtained |
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| Exercise 1.1.19 Referring to a microscope, state the function of the rheostat |
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| used to vary the intensity of light |
