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# BIOD 171 – MODULE 4 EXAM GUIDE
**ACADEMIC YEAR:** 2026/2027
**FOCUS AREA:** MICROBIAL GROWTH,
CULTURE MEDIA, AND CONTROL METHODS
## Exam Structure
This guide contains **100+ verified questions** divided into four
sections:
- **Part I:** True or False (20 questions)
- **Part II:** Multiple Choice (40 questions)
- **Part III:** Fill in the Blank / Matching (20 questions)
- **Part IV:** Lab Application & Case Studies (20 questions)
- **Answer Key:** Provided at the end with rationales.
---
## Part I: True or False (20 Questions)
*Determine if the following statements are True or False.*
1. **Question:** A virus is considered a microorganism.
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- **Answer:** False. Viruses are not living and are classified as
microbes, not microorganisms .
2. **Question:** The smallest biological unit of life is the molecule.
- **Answer:** False. The cell is the smallest biological unit of life .
3. **Question:** Growth media is best suited for distinguishing
between two similar species of bacteria.
- **Answer:** False. Differential media is best for distinguishing;
growth media simply supports growth .
4. **Question:** Chocolate agar gets its brown color from cocoa to
produce an enriched media.
- **Answer:** False. The color comes from "cooked" (lysed) red
blood cells .
5. **Question:** LB agar is classified as a selective, non-differential
media.
- **Answer:** False. LB agar is basic (non-selective) and supports
most microbes .
6. **Question:** The visualization of colonies on a petri dish represents
bacterial cells that have often multiplied a million times over.
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- **Answer:** True. A single colony originates from one cell
multiplying millions of times .
7. **Question:** The purpose of a quadrant streak is to expand a
bacterial population.
- **Answer:** False. The purpose is to isolate individual colonies
(pure culture) .
8. **Question:** When performing a dilution streak, a new (or
sterilized) loop is not required for each phase as long as the bacterial
culture is pure.
- **Answer:** False. A new loop is required for each phase to
establish a dilution gradient .
9. **Question:** To restrict the growth of a pathogenic microbe, a
researcher might decrease an incubator from 37°C to 25°C.
- **Answer:** True. Lower temperatures slow the growth of
pathogens adapted to body temperature .
10. **Question:** Archaea, a eukaryotic class of microorganisms, is
capable of surviving harsh environments.
- **Answer:** False. Archaea are prokaryotic .
11. **Question:** All multicellular microorganisms classified as
Animalia are heterotrophic.
# BIOD 171 – MODULE 4 EXAM GUIDE
**ACADEMIC YEAR:** 2026/2027
**FOCUS AREA:** MICROBIAL GROWTH,
CULTURE MEDIA, AND CONTROL METHODS
## Exam Structure
This guide contains **100+ verified questions** divided into four
sections:
- **Part I:** True or False (20 questions)
- **Part II:** Multiple Choice (40 questions)
- **Part III:** Fill in the Blank / Matching (20 questions)
- **Part IV:** Lab Application & Case Studies (20 questions)
- **Answer Key:** Provided at the end with rationales.
---
## Part I: True or False (20 Questions)
*Determine if the following statements are True or False.*
1. **Question:** A virus is considered a microorganism.
,2|Page
- **Answer:** False. Viruses are not living and are classified as
microbes, not microorganisms .
2. **Question:** The smallest biological unit of life is the molecule.
- **Answer:** False. The cell is the smallest biological unit of life .
3. **Question:** Growth media is best suited for distinguishing
between two similar species of bacteria.
- **Answer:** False. Differential media is best for distinguishing;
growth media simply supports growth .
4. **Question:** Chocolate agar gets its brown color from cocoa to
produce an enriched media.
- **Answer:** False. The color comes from "cooked" (lysed) red
blood cells .
5. **Question:** LB agar is classified as a selective, non-differential
media.
- **Answer:** False. LB agar is basic (non-selective) and supports
most microbes .
6. **Question:** The visualization of colonies on a petri dish represents
bacterial cells that have often multiplied a million times over.
, 3|Page
- **Answer:** True. A single colony originates from one cell
multiplying millions of times .
7. **Question:** The purpose of a quadrant streak is to expand a
bacterial population.
- **Answer:** False. The purpose is to isolate individual colonies
(pure culture) .
8. **Question:** When performing a dilution streak, a new (or
sterilized) loop is not required for each phase as long as the bacterial
culture is pure.
- **Answer:** False. A new loop is required for each phase to
establish a dilution gradient .
9. **Question:** To restrict the growth of a pathogenic microbe, a
researcher might decrease an incubator from 37°C to 25°C.
- **Answer:** True. Lower temperatures slow the growth of
pathogens adapted to body temperature .
10. **Question:** Archaea, a eukaryotic class of microorganisms, is
capable of surviving harsh environments.
- **Answer:** False. Archaea are prokaryotic .
11. **Question:** All multicellular microorganisms classified as
Animalia are heterotrophic.
