front 1 How many nanometers make up 1 micrometer? | back 1 1000 |
front 2 How many micrometers make up 1 nanometer? | back 2 0.001 |
front 3 What is the path of light in the compound light microscope? | back 3 Light rays from an illuminator pass through a condenser, which directs the light rays through a specimen. Light rays pass through the objective lens. It is transmitted through the body tube to the ocular lens. |
front 4 The ability of the lenses to distinguish two points. | back 4 Resolution |
front 5 Shorter wavelengths of light provide what type of resolution? | back 5 Greater |
front 6 Dark objects are visible against a bright background; | back 6 Brightfield |
front 7 Used to examine live microorganisms that either are invisible in the ordinary light microscope, cannot be stained by standard methods, or are so distorted by staining that their characteristics are obscured. 1 | back 7 Brightfield |
front 8 Useful because the internal structures of a cell become more sharply defined, permitting detailed examination of living microorganisms. | back 8 Phase-Contrast Microscope |
front 9 Is it necessary to fix or stain a specimen when using Phase-Contract microscopy? | back 9 No. |
front 10 Uses the ability of substances to absorb short wavelengths of lights and give off light at a longer wavelength. | back 10 Fluorescence |
front 11 Brings together two sets of light rays, direct rays and diffracted rays, to form an image | back 11 Phase-Contrast |
front 12 What are cells stained with if they do not naturally fluoresce? | back 12 Fluorochromes |
front 13 Measures sound waves that are reflected back from a specimen; used to study cells attached to surfaces | back 13 Scanning Acoustic |
front 14 What is the resolution of the Scanning Acoustic Microscope? | back 14 1 micrometer |
front 15 Used for images that are too small to be seen with light microscopes, such as viruses | back 15 Electron Microscope |
front 16 A beam of electrons passes through ultrathin sections of a specimen, then through an electromagnetic lens, then focused on a projector lens. | back 16 Transmission Electron Microscope |
front 17 What microscope has specimens that may be stained with heavy-metal salts for contrast? | back 17 Transmission Electron Microscope |
front 18 What is the resolution and magnification of a Transmission Electron Microscope? | back 18 10 pm and 10,000 to 100,000. |
front 19 What is the resolution and magnification of the Scanning Electron microscope? | back 19 10 nm; 1,000 to 10,000. |
front 20 An electron gun produces a beam of electrons that scans the surface of an entire specimen; secondary electrons emitted from the specimen produce a three-dimensional image. | back 20 Scanning Electron Microscope |
front 21 Do gram-positive or gram-negative bacteria have a thick peptidoglycan cell wall? | back 21 Gram-positive |
front 22 Which bacteria has a layer of lipopolysaccharides (LPS)? | back 22 Gram-negative |
front 23 What is the first step of gram staining? | back 23 Application of crystal violet (purple dye) |
front 24 What is the second step of gram staining? | back 24 Application of iodine (mordant) |
front 25 What is the third step of gram staining? | back 25 Alcohol wash (decolorization) |
front 26 What is the final step of gram staining? | back 26 Application of safranin (counterstain) |
front 27 Which microscope shows internal structures and the outline of the transparent covering? | back 27 Brightfield Microscope |
front 28 In which steps are gram positive and gram negative bacteria the same colors? | back 28 Steps 1 and 2. |
front 29 What color are the gram-negative bacteria in the third step? | back 29 Colorless, which is why safranin is applied. |
front 30 In step 4, what color are gram-negative bacteria? | back 30 Pink. |
front 31 What method is the most important staining techniques in medical microbiology? | back 31 Gram Method |
front 32 True or false: Gram staining results are universally applicable? | back 32 False, some bacterial cells stain poorly or not at all. |
front 33 Is gram-positive or gram-negative bacteria more resilient to antibiotics? Why? | back 33 Gram-negative because antibiotics cannot penetrate the LPS layer. |
front 34 What stain differentiates bacteria into two distinct groups? | back 34 The acid-fast stain. |
front 35 Binds strongly to bacteria that have a waxy material in their cell walls. | back 35 The acid-fast stain. |
front 36 What stain is used to identify Mycobacterium and Nocardia? | back 36 Acid-fast stain |
front 37 What stain is applied during acid-fast in the first step? | back 37 Carbolfuchsin |
front 38 What is the second step in acid-fast staining and why is it performed? | back 38 The slide is gently heated for several minutes. Heating enhances penetration and retention of the dye. |
front 39 In the third step of acid-fast staining, what is the slide washed with? | back 39 Water. |
front 40 What is the fourth step of acid-fast staining and what does it do? | back 40 The slide is treated with acid-alcohol. It removes the red stain from bacteria that are not acid-fast. |
front 41 What color do the acid-fast microorganisms appear to be? | back 41 Red. |
front 42 After decolorization, what color are non-acid-fast bacteria? | back 42 Colorless. |
front 43 What color counterstain is applied in the final step of acid-fast stain? | back 43 Methylene blue. |
front 44 What is negative staining used for? | back 44 Determining cell size and arrangement; It can also be used to stain cells that are too delicate to be heat-fixed. |