BIOD 171: MODULE 4 EXAM WITH CORRECT QUESTIONS AND ANSWERS 2025

BIOD 171: MODULE 4 EXAM WITH
CORRECT QUESTIONS AND ANSWERS
2025

 T/F: Growth media is best suited for distinguishing between two similar species of

bacteria - CORRECT-ANSWERSFalse



 growth media is designed to simply support (and not restrict) microbial growth

 A researcher is asked to determine which of two vials contains E coli and which contains

salmonella. Knowing both are Gram-negative while only one of them is capable of

fermenting lactose, which type of media would be best suited? - CORRECT-

ANSWERSDifferential media

 What are the requirements of a fastidious microbe? - CORRECT-ANSWERSA fastidious

microbe is an organism with complex growth requirements and will not grow without

then. Enriched medias thus contain these specific and essential nutrients required for the

growth of a particular subset of microorganisms.

 T/F: LB agar is classified as a non-selective, non-differential media - CORRECT-

ANSWERSTrue

 The polysaccharide-based hardening agent added to LB media to produce LB agar is

derived from what? - CORRECT-ANSWERSSeaweed extract

 Blood agar is which type of medium? Select all that apply:

- Selective and Differential

- Enriched

, - Differential

- Selective - CORRECT-ANSWERS- Enriched

- Differential

 Match the following hemolytic class with its description of activity:

 Alpha hemolysis

 Beta hemolysis

 Gamma hemolysis



- No change

- Greenish-brown color

- Distinct zone of clearing - CORRECT-ANSWERS1. Alpha hemolysis- Greenish-

brown color (B)

 2. Beta hemolysis- Distinct zone of clearing (C)

 Gamma hemolysis- No change (A)

 Match the following hemolytic class with its description of activity:



 Alpha hemolysis

 Beta hemolysis

 Gamma hemolysis



- No hemolytic activity

- Incomplete hemolytic activity