Technical Microbiology ch2
A virus that is 150 nm (nanometers) in diameter would be _____ Um (micrometers) in diameter.
0.150 um
Order the following choices to reflect the correct order of steps in the process of sporogenesis.
1. Endospore formation is initiated in response to environmental signals. 2. Vegetative cell becomes a sporangium. 3. A forespore forms, and protective layers are deposited around it. 4. Lysis frees the mature spore, which can now remain dormant for thousands of years.
Select the elements necessary for good microscopy.
Adequate magnification Contrast Resolution
Which 3 of the following are needed to prepare a hanging drop slide? A. A standard glass B. Sealant C. An anionic dye D. A depression slide E. A Coverslip F. Metal coating
B. Sealant D. Depression slide E. A coverslip
Which of the following media can be described precisely as to its chemical content? A. Brain-heart infusion broth B. Complex C. Defined D. General Purpose
C. Defined
_______ is part of the Five I's of culturing microorganisms and is based on visual observation of microscopic and macroscopic growth characteristics.
Inspection
Match the staining technique to the appropriate example.
Methylene blue - simple stain Gram stain - Differential stain Endospore stain - Differential stain Flagellar stain - Special stain
When spore formation begins, the vegetative cell is referred to as the _____.
Mother cell
Which types of media contain at least one ingredient that is not chemically defined?
Nonsynthetic & Blood agar
The term used to describe a cluster of spherical bacteria is _______.
Staphylococci
T or F: Biofilms typically do not develop on healthy tissue.
TRUE
If a few drops of nutrient solution are added to one side of a bacterium's environment, what will happen?
The bacterium will have longer runs towards the nutrient, but it will still tumble at times.
What determines whether a bacterium "runs" or "tumbles" through its environment?
The direction of flagellar rotation.
Which of the following are true of biofilms?
They can lead to systemic infections.
When is sporulation initiated by spore-forming bacteria?
When nutrients are depleted or conditions become adverse.
A specimen for _______ microscopy is generally first by placing a sample on a glass slide
optical or light
Spreading a thin film made from a liquid suspension of cells on a slide and air drying it are steps involved in making a _______.
smear, smear prep, or fixed smear.
The procedure that involves applying colored chemicals (dyes) to specimens is called ________.
staining
Gram negative have a ______ layer of peptidoglycan in their cell wall. Gram positive have a ______ layer of peptidoglycan in their cell wall.
thicker thinner
General purpose media ________. (multiple answers)
usually contain a mixture of nutrients. are usually non-synthetic. grow a broad spectrum. include nutrient agar and broth.
Which of the following is/are prone to biofilm accumulation? A. Catheters B. Artificial heart valves C. Teeth D. All of the choices are correct
D) All of the choices are correct.
Match the media with their general intended purpose or category.
Enriched - Thayer Martin (chocolate) agar Selective & differential - MacConkey agar General purpose- Nutrient agar Anaerobic - Reducing media Differential - Urea broth
T or F: A defined medium differs from a complex medium in that the chemical composition of the defined medium cannot be precisely determined.
FALSE
T or F: Bacteria are larger than human cells
FALSE
T or F: Biofilms are often sensitive to antibiotics.
FALSE
T or F: selective media cannot be differential.
FALSE
T or F: Bacteria are only visible with a electron microscope.
False
What motility structure is used for bacterial chemotaxis?
Flagella
Sabouraud's agar restricts the growth of bacteria and is an example of a ________ medium, whereas Mannitol salt agar can determine which species pf Staphylococcus is present, making it an example of a _______ medium.
Selective Differential
The resolving power of electron microscopes is much better than the resolving power of light microscopes because the wavelength of electron beams is ________ than the wavelength of visible light.
Shorter
What general type of stain is used to separate types of bacteria based on their cellular structures?
Differential
What is the stimulus for chemotaxis?
Chemicals
