Microbial Growth & Nutrition

Question 1

On an agar plate, a discrete colony arising from a single parent cell is known as:

Answer 1

Clones

Question 2

What are the 6 major elements in an organism?

Answer 2

• Carbon
• Hydrogen
• Nitrogen
• Oxygen
• Sulfur
• Phosphorus

Question 3

Obligate aerobes grow ___ oxygen, while obligate anaerobes grow ____ oxygen (with or without)

Answer 3

With, without

Question 4

Give an example of a microaerophile (grow best in low oxygen concentrations)

Answer 4

Streptococcus

Question 5

Anabolism/growth often ceases because of insufficient ____ (element)

Answer 5

Nitrogen

Question 6

Name the 3 physical requirements for growth of microorganisms

Answer 6

1. Temperature
2. pH
3. Osmolarity

Question 7

___ can multiply in the refrigerator

Answer 7

Psychrophiles

Question 8

____ grow best inside the human body (37 degrees Celsius. These are pathogens)

Answer 8

Mesophiles

Question 9

With respect to pH, what group do most human pathogens belong to? (They grow best around neutral pH)

Answer 9

Neutrophiles

Question 10

Helicobacter pylori is found in the stomach, what group does it fit in in regards to pH?

Answer 10

Neutrophile (It was once thought to be an acidophile, but thats not the case)

Question 11

A common isolation technique for obtaining pure cultures:

Answer 11

Streaking (streak plate)

Question 12

A polysaccharide from marine algae

Answer 12

Agar

Question 13

Best method for long-term preservation of bacterial cultures?

Answer 13

Lyophilization (freeze-drying)

Question 14

Serial dilution and viable plate counts, membrane filtration, and microscopic counts are all ___ methods for measuring microbial reproduction

Answer 14

Direct

Question 15

Dry weight and turbidity (A600) are ____ methods for measuring microbial growth

Answer 15

Indirect

Question 16

Quick and dirty way to measure microbial growth?

Answer 16

Spectrophotometer

Question 17

List the 4 phases of microbial growth from start to finish when a medium is inoculated:

Answer 17

1. Lag phase
2. Log phase (exponential growth)
3. Stationary phase
4. Death phase