Microbiology 260 Lab Quiz_ Updated Questions and Answers 100% Already Graded A+ Excel

Microbiology 260 Lab Quiz_ Updated Questions and Answers 100% Already Graded A+ Excel Classification of bacteria based on cell wall structure: Describe a positive cell wall. - CORRECT ANSWER-thick peptidoglycan layer (NAM/NAG with tetrapeptide bridge) containing teichoic and lipoteichoic acid, easier to kill Please describe a gram positive cell wall (will need to know how to label on diagram on test) (prokaryotic) - CORRECT ANSWER-1. Thick peptidoglycan layer 2. Contains teichoic and lipoteichoic acids What is a gram negative cell wall (will need to know how to label on diagram on test) (prokaryotic) - CORRECT ANSWER-1. Thin peptidoglycan layer and an outer membrane that contains lipopolysaccharide, phospholipids, and protein. 2. The periplasmic space between the cytoplasmic and outer membranes contains transport, degenerative, and cell wall synthetic proteins. 3. the outher membrane is joined to the cytoplasmic membrane at adhesion points and is attached to the peptidoglycan lipoprotin links. What are the basic shapes of bacteria? - CORRECT ANSWER-Cocci: round ball Bacilli: rod Spririlla: spiral Vibrio: comma Mycoplasma: no shape (lacking cell wall) Please draw a cocci bacteria shape. - CORRECT ANSWER- Please draw a bacilli bacteria shape. - CORRECT ANSWER- Please draw a spirillum bacteria shape. - CORRECT ANSWER- vibrio bacteria shape - CORRECT ANSWER- What is a light microscope? - CORRECT ANSWER-More common, magnify up to 2,000x, image viewed through glass ocular lens, image produced by light rays, specimen on glass slide, specimen may be alive, doesn't always require special stains/treatment, colored images produced What are the different types of microscopes? - CORRECT ANSWER-1. Brightfield 2. Darkfield 3. Phase contrast 4. Flouresence/UV 5. Confocal 6. two-photon Described a Brightfield microscope. - CORRECT ANSWER-most common (images on bright background); used for live specimens Described a Darkfield microscope. - CORRECT ANSWER-live specimen, bright image on dark background Describe a Phase contrast microscope. - CORRECT ANSWER-live specimen, high res images without staining, useful for live specimens and special structures (endospores, organelles) Described a fluorescence/UV microscope. - CORRECT ANSWER-distinguish bw live/dead cells, disease diagnosis (common in medical lab) Describe a confocal microscope. - CORRECT ANSWER-3D viewing (biofilms), focuses on all angles/planes, thick specimens Describe a two-photon microscope. - CORRECT ANSWER-infrared light, deep/thick specimens (biofilms) what is an electron microscope? - CORRECT ANSWER-Less common, magnification up to 1,000,000x, image produced by electron beam, viewed through fluorescent screen (to avoid eye damage), specimen placed on copper mesh, must be dead, requires special treatment/stains, only B/W images produced What are the two types of electron microscopes? - CORRECT ANSWER-1. Transmission Electron Microscope (TEM)2. Scannning Electron Microscope (SEM): Described a Transmission Electron Microscope (TEM) - CORRECT ANSWER-shoots beam through specimen to see inside cellular details Described a Scanning Electron Microscope (SEM). - CORRECT ANSWER-scans beam back and forth over the surface to produce 3D image What is the difference between magnification and resolution? - CORRECT ANSWER-Magnification is enlargement of an object while resolution is the microscopes ability too differentiate bw two objects that are very close together. Why do most of our bacteria need to incubate at 37 degrees Celsius? - CORRECT ANSWER-Most bacteria grow well in temperature range of 20 to 40 degrees at very high temperature bacterial protein get denatured. Hence the 37 degree is considered optimum best temp for bacterial growth What charge Bacteria has ? Which type of dye it will take acidic or basic dye ? - CORRECT ANSWER-Bacteria has negative charge, attracts basic dye (as basic dye has a positive charge), the bacteria is attracted to the dye, and the bacteria is stained. Acidic dyes which possess a negative charge is repeld by bacteria, therefor the dye stains the background. What are the three types of staining techniques? - CORRECT ANSWER-1. Simple staining 2. Differential staining 3. Special staining What is simple staining? - CORRECT ANSWER-uses 1 stain to show shapes/arrangements of colonies; positive/negative staining What is differential staining? - CORRECT ANSWER--uses two stains (primary/counter stains) to show differences within the culture -Gram stain is most common =gram positive = blue/violet -gram negative = pink/red) -Gram staining, acid-fast staining, endospore staining What is special staining? - CORRECT ANSWER-used to identify structures (endospores/capsule/flagella) What are the type type of dyes? - CORRECT ANSWER-- Basic dyes: cationic, possess a positive charge; bacteria is attracted to the dye, dye stains bacteria - Acidic dyes: anionic, possess a negative charge; bacteria repels dye, dye stains the background Describe the following flagellar arrangement for monotrichous. - CORRECT ANSWER-single flagellum at one pole Describe the following flagellar arrangement for Lophotrichous. - CORRECT ANSWER-many flagella at one pole