Quiz 2

Question 1

What is the solidifying agent used in microbiological media? Where does this compound originate?

Answer 1

Agar, which comes from the cell walls of red algae.

Question 2

How should Petri dishes be labeled?

Answer 2

Must be labeled on the bottom, around the outside edge of the dish with a sharpie.

1. Name
2. Date
3. Media
4. Source

Question 3

What is the definition of a ‘general medium’? Please name a type of general medium used last week?

Answer 3

A general medium used to grow any microbe, not a specific type of microbe. (General purpose media) TSA (trypticase soy agar) and TSB (trypticase soy broth) were used.

Question 4

What is the definition of a ‘selective medium’? Please name a type of specific medium used in last week’s lab. Why did we use this medium? How, specifically, does it work?

Answer 4

Selective medium promotes the growth of specific microbes, we used sabouraund dextrose agar to select for fungal growth. The media has a low pH (acidic) and high sugar content.

Question 5

What does it mean to say bacteria are ubiquitous?

Answer 5

Bacteria are everywhere!

Question 6

What does it mean to say a broth is ‘turbid’?

Answer 6

Turbid broth appears cloudy, and is an indication of bacterial growth.