Bacterial smears are heat fixed before staining to: Group of answer choices Enable stain to bind to cells Make the membranes more permeable Lyse the bacterial cells Make the cell walls more permeable Kill and adhere cells to the slide

Bacterial smears are fixed before staining toGroup of answer choicesmake the cells visible.accept stain.affix the cells to the slide.make their walls permeable.

Assume you stain Bacillus by applying malachite green with heatand then counterstain with safranin. Through the microscope, thegreen structures area. cell walls.b. capsules.c. endospores.d. flagella.e. impossible to identify.2. Live cells at a depth of 1 mm and with reduced phototoxicity canbe viewed through aa. darkfield microscope.b. fluorescence microscope.c. two-photon microscope.d. confocal microscope.e. phase-contrast microscope.3. Capsule staining is a difficult technique to accomplish becausea. capsules are antigenic.b. capsules repel most biological dyes.c. capsular materials are water soluble.d. the specimen has to be mixed with fine colloidal suspension ofIndia ink or nigrosin.4. You observe that the cells of a Gram-stained urine sample appearpurple in brightfield microscopy, with cocci-shaped bacteriaarranged in chains. You conclude:a. the urine sample is too old.b. the smear is too thick.c. gram staining is unsuitable for this sample.d. the cells are gram-positive.e. none of the above.5. Which of the following is not a functionally analogous pair of stains?a. nigrosin and malachite greenb. crystal violet and carbolfuchsinc. safranin and methylene blued. ethanol-acetone and acid-alcohole. All of the above pairs are functionally analogous.6. Which of the following pairs is mismatched?a. capsule—negative stainb. cell arrangement—simple stainc. cell size—negative staind. Gram stain—bacterial identificatione. none of the above7. Assume you stain Clostridium by applying a basic stain,carbolfuchsin, with heat, decolorizing with acid-alcohol, andcounterstaining with an acidic stain, nigrosin. Through themicroscope, the endospores are 1 , and the cells are stained2 .a. 1—red; 2—blackb. 1—black; 2—colorlessc. 1—colorless; 2—blackd. 1—red; 2—colorlesse. 1—black; 2—red8. Assume that you are viewing a Gram-stained field of red cocci andblue rods through the microscope. You can safely conclude thatyou havea. made a mistake in staining.b. two different species.c. old bacterial cells.d. young bacterial cells.e. none of the above9. In 1996, scientists described a new tapeworm parasite that hadkilled at least one person. The initial examination of the patient’sabdominal mass was most likely made usinga. brightfield microscopy.b. darkfield microscopy.c. electron microscopy.d. phase-contrast microscopy.e. fluorescence microscopy

Gram staining is based on:a) the ability of the bacterial cell wall to retain crystal violet dyeb) the lysis of bacterial cellsc) differences in bacterial shape and sized) growth of bacterial cells

What are the two main purposes of heat fixing? 1. to kill the bacteria2. to 'stick' the bacteria to the slide1. to get a thin layer of bacteria2. to make sure you only have one kind of bacteria

Assume you stain Bacillus by applying malachite green with heat and then counterstaining with safranin. Through the microscope, the green structures areGroup of answer choicesflagella.capsules.The answer cannot be determined.endospores.cell walls.