Review Questions for Quiz # 6 from Lesson Content 8 (10 MCQ)

Is media a single or plural form? What is the media? What are the uses of media?

Media is considered a plural form; it refers to the various means of communication and is used for transmitting information.

All media must be __ before use and what does it destroy?

All media must be sterilized before use and it destroys any contaminating microorganisms.

Liquid media (broth) is used to culture __?

Liquid media is used to culture microorganisms.

What are some examples of nutrient components in liquid media?

Examples include peptone, beef extract, and yeast extract.

Solid media is used for __?

Solid media is used for isolating and growing bacteria.

What is the percentage of agar added to solid media?

Agar is typically added at a concentration of 1.5-2%.

At what temperature does agar get solidified?

Agar solidifies at approximately 37 degrees Celsius.

Name some examples of solid media.

Examples include nutrient agar, blood agar, and MacConkey agar.

When is agar gel formed?

Agar gel is formed when agar is cooled below its melting point after being heated.

What is semisolid media and how much percentage of agar does it contain?

Semisolid media contains 0.5-0.7% agar and is used to examine motility of microorganisms.

Name some examples of semisolid media.

Examples include motility media and gelatin stab media.

What are the requirements considered when choosing a suitable medium for microorganisms?

Considerations include nutrients, pH, consistency, and oxygen requirements.

What is the type of water used for preparing the media?

Distilled water is used for preparing media; hard tap water cannot be used due to impurities.

What is an autotroph and heterotroph?

Autotrophs produce their own food, while heterotrophs obtain food from other organisms.

Most bacteria grow best around what __ environment in terms of pH?

Most bacteria grow best around a neutral pH environment, typically around pH 7.

What is used as an energy source in media?

Carbohydrates, such as glucose, are commonly used as energy sources in media.

What does general purpose media usually contain a source of?

General purpose media usually contains a source of nutrients like peptones and extracts.

Name some general-purpose media.

Examples include tryptic soy agar and nutrient agar.

What are examples of anaerobic media?

Examples include anaerobic blood agar and thioglycollate broth.

What is selective media?

Selective media is designed to favor the growth of particular microorganisms while inhibiting others.

Name some examples of selective media.

Examples include Manitol salt agar and Luria-Bertani (LB) agar.

Review steps to preparation of culture media.

Steps include selecting the medium, measuring ingredients, dissolving, sterilizing, and cooling.

Why do we use 5% tartaric acid when preparing media such as nutrient agar?

5% tartaric acid is used to adjust the pH of the medium.

We use filtration as a way of sterilization for what type of organisms?

Filtration is used for sterilizing heat-sensitive liquids and organisms.

Whole blood is added to molten agar to make blood agar at what temperature?

Whole blood is added to molten agar at approximately 45-50 degrees Celsius.

What is stock culture?

A stock culture is an established culture of microorganisms maintained for future use.

What is sub-culturing?

Sub-culturing is the transfer of microorganisms from one medium to another to maintain a culture.

Review quality control section.

Quality control ensures that media and procedures yield reliable and consistent results.