BIOL 271 MICROBIOLOGY W/ LAB FINAL
EXAM REVIEW | LOCKDOWN BROWSER |
PORTAGE LEARNING
Core Domains
• Foundations of Microbiology and Microbial Classification
• Prokaryotic Cell Structure and Function
• Eukaryotic Cell Structure and Function
• Microbial Metabolism and Growth
• Microbial Genetics and Molecular Biology
• Control of Microbial Growth (Physical and Chemical Methods)
• Host-Microbe Interactions and Immunology
• Pathogenic Microbiology and Disease Transmission
• Laboratory Techniques and Diagnostic Microbiology
• Antimicrobial Agents and Resistance
Introduction
This comprehensive final exam review for BIOL 271 Microbiology w/Lab at Portage
Learning is designed to prepare students for the proctored final examination
administered via LockDown Browser. The exam integrates knowledge from all six
modules, covering foundational concepts of microbiology including cell structure
and function, metabolism, genetics, microbial control, immunology, pathogenesis,
and diagnostic laboratory techniques. Utilizing a multiple-choice format with
scenario-based questions, this review tests critical thinking and application of
microbiological principles essential for understanding infectious diseases and their
management. Emphasis is placed on real-world application, laboratory safety, and
,evidence-based practice. Each question is accompanied by a detailed rationale to
reinforce learning and enhance comprehension for the 2026/2027 academic year.
SECTION ONE: QUESTIONS 1-100
1. Which of the following correctly lists the four macromolecules common to
all cells?
A. Proteins, carbohydrates, lipids, nucleic acids
B. Proteins, carbohydrates, lipids, vitamins
C. Proteins, nucleic acids, minerals, carbohydrates
D. Carbohydrates, lipids, nucleic acids, water
A
RATIONALE: All cells are composed of four major macromolecules: proteins,
carbohydrates, lipids, and nucleic acids (DNA/RNA). These organic molecules are
essential for cellular structure, function, and energy storage.
2. A virus is classified as a microbe. True or False?
A. True
B. False
A
RATIONALE: Viruses are classified as microbes (microorganisms) even though
they are acellular (lacking cells) and not considered living organisms. They are
studied in microbiology because they are infectious agents that replicate within
host cells.
3. What is the smallest biological unit of life?
A. The cell
B. The nucleus
C. The atom
D. The molecule
, A
RATIONALE: The cell is the smallest biological unit of life. All living organisms
are composed of cells, which are the basic structural and functional units of life.
4. Which of the following best describes the nucleoid region of a prokaryotic
cell?
A. A membrane-bound nucleus containing DNA
B. A region containing DNA that is not enclosed by a membrane
C. An organelle responsible for protein synthesis
D. A structure that produces ATP
B
RATIONALE: Prokaryotic cells lack a true membrane-bound nucleus. Instead,
their DNA is located in a region called the nucleoid, which is not enclosed by a
membrane.
5. Which of the following best describes the structural difference between
Gram-positive and Gram-negative bacteria?
A. Gram-positive bacteria have an outer membrane; Gram-negative bacteria do not
B. Gram-positive bacteria have a thick peptidoglycan layer; Gram-negative bacteria
have a thin peptidoglycan layer and an outer membrane
C. Gram-positive bacteria have no cell wall; Gram-negative bacteria have a cell wall
D. Gram-positive bacteria are spherical; Gram-negative bacteria are rod-shaped
B
RATIONALE: The structural difference between Gram-positive and Gram-
negative bacteria is that Gram-positive bacteria have a thick peptidoglycan layer in
their cell wall, while Gram-negative bacteria have a thin peptidoglycan layer and an
outer membrane.
6. A micrometer (µm) is defined as:
, A. 10⁻³ meters
B. 10⁻⁶ meters
C. 10⁻⁹ meters
D. 10⁻¹² meters
B
RATIONALE: A micrometer (µm) is defined as 10⁻⁶ meters (one-millionth of a
meter). This unit is commonly used to measure microorganisms.
7. Which of the following is a physical method utilized to prevent infections?
A. Antibiotics
B. The sloughing off of the epidermal layer
C. Antiseptics
D. Vaccines
B
RATIONALE: The sloughing off of the epidermal layer is a physical method of
preventing infections. The skin serves as a physical barrier, and the shedding of
dead skin cells helps remove microorganisms.
8. Which microscope objective lens should be used with immersion oil?
A. The 10x objective lens
B. The 40x objective lens
C. The 100x objective lens
D. The 4x objective lens
C
RATIONALE: The 100x oil immersion objective lens requires immersion oil to
increase resolution and numerical aperture. The oil prevents light refraction and
allows for clearer visualization of bacteria.
9. What is the correct order of the Gram stain reagents?
EXAM REVIEW | LOCKDOWN BROWSER |
PORTAGE LEARNING
Core Domains
• Foundations of Microbiology and Microbial Classification
• Prokaryotic Cell Structure and Function
• Eukaryotic Cell Structure and Function
• Microbial Metabolism and Growth
• Microbial Genetics and Molecular Biology
• Control of Microbial Growth (Physical and Chemical Methods)
• Host-Microbe Interactions and Immunology
• Pathogenic Microbiology and Disease Transmission
• Laboratory Techniques and Diagnostic Microbiology
• Antimicrobial Agents and Resistance
Introduction
This comprehensive final exam review for BIOL 271 Microbiology w/Lab at Portage
Learning is designed to prepare students for the proctored final examination
administered via LockDown Browser. The exam integrates knowledge from all six
modules, covering foundational concepts of microbiology including cell structure
and function, metabolism, genetics, microbial control, immunology, pathogenesis,
and diagnostic laboratory techniques. Utilizing a multiple-choice format with
scenario-based questions, this review tests critical thinking and application of
microbiological principles essential for understanding infectious diseases and their
management. Emphasis is placed on real-world application, laboratory safety, and
,evidence-based practice. Each question is accompanied by a detailed rationale to
reinforce learning and enhance comprehension for the 2026/2027 academic year.
SECTION ONE: QUESTIONS 1-100
1. Which of the following correctly lists the four macromolecules common to
all cells?
A. Proteins, carbohydrates, lipids, nucleic acids
B. Proteins, carbohydrates, lipids, vitamins
C. Proteins, nucleic acids, minerals, carbohydrates
D. Carbohydrates, lipids, nucleic acids, water
A
RATIONALE: All cells are composed of four major macromolecules: proteins,
carbohydrates, lipids, and nucleic acids (DNA/RNA). These organic molecules are
essential for cellular structure, function, and energy storage.
2. A virus is classified as a microbe. True or False?
A. True
B. False
A
RATIONALE: Viruses are classified as microbes (microorganisms) even though
they are acellular (lacking cells) and not considered living organisms. They are
studied in microbiology because they are infectious agents that replicate within
host cells.
3. What is the smallest biological unit of life?
A. The cell
B. The nucleus
C. The atom
D. The molecule
, A
RATIONALE: The cell is the smallest biological unit of life. All living organisms
are composed of cells, which are the basic structural and functional units of life.
4. Which of the following best describes the nucleoid region of a prokaryotic
cell?
A. A membrane-bound nucleus containing DNA
B. A region containing DNA that is not enclosed by a membrane
C. An organelle responsible for protein synthesis
D. A structure that produces ATP
B
RATIONALE: Prokaryotic cells lack a true membrane-bound nucleus. Instead,
their DNA is located in a region called the nucleoid, which is not enclosed by a
membrane.
5. Which of the following best describes the structural difference between
Gram-positive and Gram-negative bacteria?
A. Gram-positive bacteria have an outer membrane; Gram-negative bacteria do not
B. Gram-positive bacteria have a thick peptidoglycan layer; Gram-negative bacteria
have a thin peptidoglycan layer and an outer membrane
C. Gram-positive bacteria have no cell wall; Gram-negative bacteria have a cell wall
D. Gram-positive bacteria are spherical; Gram-negative bacteria are rod-shaped
B
RATIONALE: The structural difference between Gram-positive and Gram-
negative bacteria is that Gram-positive bacteria have a thick peptidoglycan layer in
their cell wall, while Gram-negative bacteria have a thin peptidoglycan layer and an
outer membrane.
6. A micrometer (µm) is defined as:
, A. 10⁻³ meters
B. 10⁻⁶ meters
C. 10⁻⁹ meters
D. 10⁻¹² meters
B
RATIONALE: A micrometer (µm) is defined as 10⁻⁶ meters (one-millionth of a
meter). This unit is commonly used to measure microorganisms.
7. Which of the following is a physical method utilized to prevent infections?
A. Antibiotics
B. The sloughing off of the epidermal layer
C. Antiseptics
D. Vaccines
B
RATIONALE: The sloughing off of the epidermal layer is a physical method of
preventing infections. The skin serves as a physical barrier, and the shedding of
dead skin cells helps remove microorganisms.
8. Which microscope objective lens should be used with immersion oil?
A. The 10x objective lens
B. The 40x objective lens
C. The 100x objective lens
D. The 4x objective lens
C
RATIONALE: The 100x oil immersion objective lens requires immersion oil to
increase resolution and numerical aperture. The oil prevents light refraction and
allows for clearer visualization of bacteria.
9. What is the correct order of the Gram stain reagents?
