Quiz 3 Flashcards
What are the terms used to describe microbial colonies on a culture plate?
The terms include form, elevation, and margin.
What are the three bacterial cell shapes observed under a microscope?
The three bacterial cell shapes are cocci, bacilli, and spirilla.
What are the bacterial arrangements used in lab?
Bacterial arrangements include singles, pairs, chains, and clusters.
How is a differential stain different from a simple stain?
A differential stain distinguishes between different types of bacteria
a simple stain colors all bacteria the same way.
Examples of differential stains include Gram stain and acid-fast stain
an example of a simple stain is methylene blue.
What is the purpose of each Gram stain reagent?
The purpose of each reagent is to differentiate bacterial cells based on their cell wall structure.
After each step: Crystal violet (purple), iodine (purple), alcohol (decolorizes), safranin (pink for Gram-negative).
What are the growth patterns of bacteria in thio media based on oxygen needs?
Growth patterns include obligate aerobes (top), facultative anaerobes (throughout), obligate anaerobes (bottom), and microaerophiles (just below the surface).
What are the details of the oxidase test?
The oxidase test determines the presence of cytochrome c oxidase in bacteria.
What are the details for MAC media?
MAC media supports the growth of Gram-negative organisms, contains lactose, and uses neutral red dye to indicate sugar fermentation.
Positive reaction: pink colonies
negative reaction: colorless colonies.
What are the details for EMB media?
EMB media supports the growth of Gram-negative organisms, contains lactose and eosin methylene blue dye to indicate sugar fermentation.
Positive reaction: dark purple/black colonies;
negative reaction: colorless colonies.
