Download GENERAL MICROBIOLOGY MIDTERM LAB EXAM WITH CORRECT AND VERIFIED ANSWERS 2025\2026 [SCORE A and more Exams Nursing in PDF only on Docsity!
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
TRUE - correct answers TRUE or FALSE: The high-dry lens will be optimal for observing multicellular fungi or algae. False - correct answers TRUE of FALSE: The oil immersion objective is necessary to determine the morphology and prokaryotes. coccus - correct answers What is the morphology? spiral - correct answers what is the morphology? Bacilli - correct answers what is the morphology? CLOTHING: Long pants, long sleeve shirts or a lab coat, safety goggles and gloves when needed. CLEANUP: Bleach lab table at beginning of lab and end of lab, wash hands at beginning of lab and end of lab. DISPOSAL: If anything breaks let instructor know, and clean up broken items, if a chemical or bacteria spill soak paper towel with cleaning solution let sit for 20 minutes then cleanup discard items in designated disposal area. BEHAVIOR: no messing around, follow lab instructions, come prepared. - correct answers LAB AND SAFETY PROCEDURES: know the proper clothing, behavior, handling of materials, including clean-up and disposal
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
objective lens - correct answers mechanical stage - correct answers base - correct answers arm - correct answers ocular lens - correct answers illuminator - correct answers condenser - correct answers coarse focusing knob - correct answers fine focusing knob - correct answers diaphragm - correct answers
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
40x total magnification - correct answers Figure out the total magnification of this problem: 4x objective lens and 10x ocular lens ocular lens - correct answers remagnifies the image formed by the obective lens body tube - correct answers transmits the image form the objective lens to the ocular lens arm - correct answers supports the body tube objective lenses - correct answers Primary lenses that magnify the specimen mechanical stage - correct answers holds the microscope slide in place condenser - correct answers focuses light through the specimen diaphragm - correct answers controls the amount of light entering the condenser illuminator - correct answers light source
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
fine focusing knob - correct answers used for focusing the specimen; used to focus and make much clearer coarse focusing knob - correct answers used for focusing the specimen; this should only be used on the lowest power of 4x, so you don't break the slide in the other powers. light intensity - correct answers adjusts the current to lamp So the magnification of the object stays in focus - correct answers why is it desirable that microscope objectives be in parfocal? oil immersion (100x) - correct answers which objective focuses closest to the slide when it is in focus? iris diaphragm and illumination controls - correct answers which controls on the microscope affect the amount of light reaching the ocular lens?
- Use an objective with a higher numerical aperture
- Use a shorter wavelength of light, and use of immersion oil - correct answers name 2 ways in which you can enhance the resolving power
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
- correct answers can you distinguish the prokaryotic organisms from the eukaryotic organisms? explain. it would be too close to the slid, not enough working distance. - correct answers why isn't the oil immersion lens used in the hanging-drop procedure? - correct answers a wet mount may be used for quick examination of fecal samples. is this most useful for identifying protozoan or bacterial parasites? bright field microscope - correct answers objects are dark and the field is light phase-contrast microscope - correct answers there are small differences in the refractive properties of the objects and the aqueous environment are transformed into corresponding variations. circular - correct answers what is the whole colony appearance? irregular - correct answers what is the whole colony appearance? biconvex - correct answers what is the whole colony appearance?
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
filamentous - correct answers what is the whole colony appearance? rhizoid (long projections) - correct answers what is the whole colony appearance? entire - correct answers what is the margin (edge)? undulate - correct answers what is the margin (edge)? lobate - correct answers what is the margin (edge)? filamentous - correct answers what is the margin (edge)? curled - correct answers what is the margin (edge)? flat - correct answers what is the elevation? raised - correct answers what is the elevation? convex - correct answers what is the elevation?
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
TSA - correct answers Tryptic Soy Agar TSB - correct answers Trypticase Soy Broth ubiquity - correct answers the state of being everywhere at once (or seeming to be everywhere at once) hanging drop and wet mount - correct answers what other methods can be used to determine motility? A solid growth site that is easier to store/transport. - correct answers what is the primary use of slants? to determine motility or if it prefers oxygen or little to no oxygen - correct answers what is the primary use of deeps? to grow large numbers - correct answers what is the primary use of broths? sterile transfer of microbes, and you don't cross contaminate.
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
After: to kill airborne microbes. - correct answers what is the purpose of flaming the loop before use and after use? so you don't kill the microbes you are transfering. - correct answers why must the loop be cool before you touch it to a culture? no, put in cooling rack needle end up, do not touch anything. - correct answers should you set down the loop to let it cool? wait about 20 to 30 seconds. - correct answers how do you determine when the loop is cool? so you don't contaminate or cross contaminate any of the microbes, agars, or broths - correct answers why is aseptic technique important? diplococci - correct answers what is the shape? staphylococci - correct answers what is the morphology? sarcina - correct answers what is the morphology? tetrad - correct answers what is the morphology?
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
bacilli - correct answers Rod shaped bacteria spirochetes - correct answers spiral shaped bacteria vibrios - correct answers curved rods streptobacilli - correct answers chains of bacilli Bacillus subtilis - correct answers Motile, gram +, bacilli enterobacter aerogenes - correct answers motile, gram - , bacilli escherichia coli - correct answers motile, gram - , bacilli Klebsiella pneumoniae - correct answers non-motile, gram - , bacilli micrococcus luteus - correct answers non-motile, gram +, coccus proteus vulgaris - correct answers motile, gram - , bacilli
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
Pseudomonas aeruginosa - correct answers motile, gram - , bacilli Staphylococcus epidermidis - correct answers non-motile, gram +, cocci staphylococcus aureus - correct answers non-motile, gram +, cocci streptococcus pneumoniae - correct answers non-motile, gram +, cocci streptococcus pyogenes - correct answers non-motile, gram +, cocci streptococcus salivarius - correct answers non-motile, gram +, cocci Bacillus subtilis - correct answers what bacteria is this? Enterobacter aerogenes - correct answers what bacteria is this? Escherichia coli - correct answers what bacteria is this? Klebsiella pneumoniae - correct answers what bacteria is this?
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
denatures bacterial enzymes, perserves microbes with minimal shrinkage or distortion when they are stained, and kills bacteria. - correct answers what is the purpose of heat-fixing the smear? removes water from the cell, and retains their structure, and adheres to the surface - correct answers another method of fixing smears is to use methanol instead of heat. how does alcohol chemically fix the bacteria? cells will distort, and the cells could break - correct answers in heat-fixing what would happen if too much heat were applied? bacteria is negatively charged so it can only absorb the stain that is positively charged. acidic stains are negatively charged and bacteria will repel the dye. - correct answers Methylene blue can be prepared as a basic stain or an acidic stain. How would the pH of the stain affect the staining of the bacteria? yes, crystal violet, safranin, because they are catatonic. - correct answers can dyes other than methylene blue be used for direct staining? briefly explain it allows bacteria to be saved and re-examined or shared. - correct answers bacteria can be seen without staining. why, then, was Koch's recommendation of fixing and staining important for the discovery of the bacterial causes of diseases?
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
yes - correct answers quality control staff in a sterilization unit of a hospital used a simple stain to determine whether bacteria were present in sterilized materials. a simple stain of sterile saline used for respiratory therapy revealed the presence of bacteria. is the saline contaminated? no heat fixing or chemicals, so bacteria is less distorted - correct answers why is the size more accurate in a negative stain than in a direct stain? to avoid contamination or spreading bacteria - correct answers why were you instructed to discard the toothpick in disinfectant? darkfield technique - correct answers what microscope technique gives a field similar in appearance to that seen in the negative stain? basic - correct answers carbolfuchsin can be used as a direct stain and as a negative stain. as a direct stain, the pH is _______________. dye and bacteria are both negatively charged making it so they repel each other. the dye stains the background and leave the bacteria clear. - correct answers unlike nigrosin, acidic congo red does not contain suspended particles, but it can give the appearance of a negative stain. what is the basis for this stain?
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
- rinse with H2O
- acid alcohol for 1 min.
- rinse with H2O
- methylene blue for 1 min.
- rinse with H2O
- blot dry endospore stain - correct answers 1. place paper over smear
- cover paper with malachite green
- steam slide for 5 minutes
- rinse with H2O
- cover with safranin for 30 seconds.
- rinse with H2O
- blot dry capsule stain - correct answers 1. acid-alcohol = 15 seconds
- rinse with H2O
- cover stain with acid fuchsin for 1 minute
- rinse with H2O
- blot dry
EXAM WITH CORRECT AND VERIFIED
ANSWERS 2025 \2026 [SCORE A]
flagella stain - correct answers 1. place a drop of H2O on slide.
- inoculate the culture
- place loop in water on slide without touching the slide at all (don't mix)
- tilt slide until water flows to opposite end.
- let air dry
- cover slide with flagella stain for 4 minutes
- rinse with H2O
- let air dry (do not blot) capsule and flagella stain - correct answers what 2 stains do you not heat fix? flagella stain - correct answers what type of stain is this? capsule stain - correct answers what type of stain is this? endospore stain - correct answers what type of stain is this? acid-fast stain - correct answers what type of stain is this?
