BIOD 171 Module 4 Exam UPDATED
Exam Questions and CORRECT Answers
Why do we need to expand a microbial population to study it? - CORRECT ANSWER -
Makes microorganisms easier to detect
Factors necessary for bacterial growth - CORRECT ANSWER - Nutrients
Temperature
pH
Growth Media - CORRECT ANSWER - liquid or solid formulated to support microbial
growth; contains nutrients
Nutrient composition of growth media - CORRECT ANSWER - carbon/energy source
sugars, amino acids, vitamin
LB Media - CORRECT ANSWER - (Lysogeny broth)
Most common media used
Known for ability to grow a vast array of microbes
Classifications of Media - CORRECT ANSWER - Selective and Differential
Selective Media - CORRECT ANSWER - allows for growth of certain microbes only;
restricts growth of others
How do selective media restrict growth of unwanted microbes? - CORRECT ANSWER -
Limits amounts of nutrients
Varies degree of pH
Various chemical additives
, Meningitis - CORRECT ANSWER - Neisseria meningitides
Grows slower than other microbes in sample
Must be grown on selective media
Differential media - CORRECT ANSWER - Used to distinguish between different, often
related, microbes.
Growth process of E. coli and Salmonella in differential media - CORRECT ANSWER -
(1) both gram negative, so can't be distinguished initially
(2) E. coli ferments lactose and turns culture red
(3) Salmonella doesn't ferment, leaves culture white/tan
Enriched Media - CORRECT ANSWER - Used to grow organisms with complex growth
requirements
Consists of essential nutrients for specific microorganisms
Solid growth media - CORRECT ANSWER - Liquid growth media with hardening agent
Agar (how it's made, function) - CORRECT ANSWER - Solid medium created with the
addition of polysaccharide derivative
Provides a solid and smooth surface on which microbes can grow
Lawn - CORRECT ANSWER - when the bacteria completely covers the surface of a petri
dish containing solid growth media
Exam Questions and CORRECT Answers
Why do we need to expand a microbial population to study it? - CORRECT ANSWER -
Makes microorganisms easier to detect
Factors necessary for bacterial growth - CORRECT ANSWER - Nutrients
Temperature
pH
Growth Media - CORRECT ANSWER - liquid or solid formulated to support microbial
growth; contains nutrients
Nutrient composition of growth media - CORRECT ANSWER - carbon/energy source
sugars, amino acids, vitamin
LB Media - CORRECT ANSWER - (Lysogeny broth)
Most common media used
Known for ability to grow a vast array of microbes
Classifications of Media - CORRECT ANSWER - Selective and Differential
Selective Media - CORRECT ANSWER - allows for growth of certain microbes only;
restricts growth of others
How do selective media restrict growth of unwanted microbes? - CORRECT ANSWER -
Limits amounts of nutrients
Varies degree of pH
Various chemical additives
, Meningitis - CORRECT ANSWER - Neisseria meningitides
Grows slower than other microbes in sample
Must be grown on selective media
Differential media - CORRECT ANSWER - Used to distinguish between different, often
related, microbes.
Growth process of E. coli and Salmonella in differential media - CORRECT ANSWER -
(1) both gram negative, so can't be distinguished initially
(2) E. coli ferments lactose and turns culture red
(3) Salmonella doesn't ferment, leaves culture white/tan
Enriched Media - CORRECT ANSWER - Used to grow organisms with complex growth
requirements
Consists of essential nutrients for specific microorganisms
Solid growth media - CORRECT ANSWER - Liquid growth media with hardening agent
Agar (how it's made, function) - CORRECT ANSWER - Solid medium created with the
addition of polysaccharide derivative
Provides a solid and smooth surface on which microbes can grow
Lawn - CORRECT ANSWER - when the bacteria completely covers the surface of a petri
dish containing solid growth media
