BIOD 171 Module 4 Exam 2026/2027 UPDATED
QUESTIONS WITH ANSWERS GRADED A+
• 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? -✓✓
Differential media
• What are the requirements of a fastidious microbe? -✓✓ A 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 -✓✓ True
• The polysaccharide-based hardening agent added to LB media to produce LB
agar is derived from what? -✓✓ Seaweed extract
• Blood agar is which type of medium? Select all that apply:
- Selective and Differential
- Enriched
- Differential
- Selective -✓✓ - Enriched
- Differential
• Match the following hemolytic class with its description of activity:
1. Alpha hemolysis
2. Beta hemolysis
, 3. Gamma hemolysis
A. No change
B. Greenish-brown color
C. Distinct zone of clearing -✓✓ 1. Alpha hemolysis- Greenish-brown color (B)
2. Beta hemolysis- Distinct zone of clearing (C)
3. Gamma hemolysis- No change (A)
• Match the following hemolytic class with its description of activity:
1. Alpha hemolysis
2. Beta hemolysis
3. Gamma hemolysis
A. No hemolytic activity
B. Incomplete hemolytic activity
C. Complete hemolytic activity -✓✓ 1. Alpha hemolysis- Incomplete hemolytic
activity (B)
2. Beta hemolysis- Complete hemolytic activity (C)
3. Gamma hemolysis- No hemolytic activity (A)
• Columbia CNA agar is most closely related to which media: -✓✓ Blood agar
CNA agar is similar to BAP as its also enriched with blood and allows for
differentiation based on hemolytic patterns
QUESTIONS WITH ANSWERS GRADED A+
• 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? -✓✓
Differential media
• What are the requirements of a fastidious microbe? -✓✓ A 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 -✓✓ True
• The polysaccharide-based hardening agent added to LB media to produce LB
agar is derived from what? -✓✓ Seaweed extract
• Blood agar is which type of medium? Select all that apply:
- Selective and Differential
- Enriched
- Differential
- Selective -✓✓ - Enriched
- Differential
• Match the following hemolytic class with its description of activity:
1. Alpha hemolysis
2. Beta hemolysis
, 3. Gamma hemolysis
A. No change
B. Greenish-brown color
C. Distinct zone of clearing -✓✓ 1. Alpha hemolysis- Greenish-brown color (B)
2. Beta hemolysis- Distinct zone of clearing (C)
3. Gamma hemolysis- No change (A)
• Match the following hemolytic class with its description of activity:
1. Alpha hemolysis
2. Beta hemolysis
3. Gamma hemolysis
A. No hemolytic activity
B. Incomplete hemolytic activity
C. Complete hemolytic activity -✓✓ 1. Alpha hemolysis- Incomplete hemolytic
activity (B)
2. Beta hemolysis- Complete hemolytic activity (C)
3. Gamma hemolysis- No hemolytic activity (A)
• Columbia CNA agar is most closely related to which media: -✓✓ Blood agar
CNA agar is similar to BAP as its also enriched with blood and allows for
differentiation based on hemolytic patterns
