Chamberlain University
2 MAXE • 242 SOIB
★ ★
C College of Nursing & Health Professions
J O U R N E Y T O E X T R A O R D I N A R Y CO M PA S S I O N AT E C A R E
EST. 1889
BIOS 242 — Examination 2
M I C R O B I A L N U T R I T I O N , G R O W T H , M E TA B O L I S M , CO N T R O L & I N F E C T I O N
INSTITUTION Chamberlain University COURSE CODE BIOS 242
PROGRAM Bachelor of Science in Nursing (BSN) ACADEMIC YEAR
EXAM TITLE Examination 2 — Fundamentals of Microbiology TOTAL QUESTIONS 25 Questions
COURSE TITLE Fundamentals of Microbiology FORMAT Multiple Choice — Select the Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question unless otherwise instructed.
▸ This examination covers microbial nutrition, growth phases, metabolism, control methods, antibiotic resistance, and infection stages.
▸ All content reflects BIOS 242 learning objectives and foundational microbiology for nursing practice.
▸ Correct answers and detailed rationales appear below each question for exam preparation purposes.
▸ Use mnemonics "Lazy Lions Sit Down" (growth phases) and "I Pat A Cat" (infection stages).
SECTION I — NUTRITION, GROWTH, METABOLISM, CONTROL, RESISTANCE & INFECTION Questions 1 – 25
1. Saprobes obtain nutrients and energy from which source?
A. Living host tissues and fluids — they are parasites
B. Dead or nonliving material — examples include fungi and bacteria
C. Sunlight through photosynthesis
D. Inorganic chemical compounds like rocks
CORRECT ANSWER B — Dead or nonliving material — examples include fungi and bacteria
RATIONALE Saprobes (saprophytes) obtain nutrients and energy from dead or nonliving organic material. They are decomposers that recycle nutrients in ecosystems — fungi
and many bacteria are saprobes. Parasites obtain nutrients from living host tissues/fluids (e.g., helminths). A mutualistic relationship benefits both organisms
(e.g., gut intestinal bacteria). This nutritional classification is based on the source of organic matter an organism uses. Understanding these ecological
relationships is fundamental to microbiology.
2. A facultative anaerobe is best described as an organism that:
A. Requires oxygen and will die without it
B. Cannot tolerate oxygen and will die if it is present
C. Prefers oxygen but can still multiply if oxygen is absent
D. Does not use oxygen at all in any circumstances
CORRECT ANSWER C — Prefers oxygen but can still multiply if oxygen is absent
RATIONALE A facultative anaerobe prefers oxygen for metabolism but can survive and multiply without it by switching to fermentation or anaerobic respiration. An aerobe
requires oxygen. An anaerobe does not use oxygen. An obligate anaerobe will die if oxygen is present. This flexibility allows facultative anaerobes to colonize
diverse environments. Many medically important bacteria (E. coli, Staphylococcus) are facultative anaerobes, which explains their ability to cause infections in
both oxygenated and oxygen-poor body sites.
3. Heterotrophs differ from autotrophs in that heterotrophs:
A. Use inorganic CO₂ to build their own organic molecules (self-feeders)
B. Must obtain carbon in organic form from other living things — examples include animals
C. Gain energy from sunlight through photosynthesis
D. Obtain energy exclusively from chemical compounds
CORRECT ANSWER B — Must obtain carbon in organic form from other living things — examples include animals
RATIONALE Heterotrophs must obtain their carbon in organic form — they are nutritionally dependent on other life forms. Examples include animals, fungi, and many
bacteria. Autotrophs use inorganic CO₂ to build their own organic molecules (self-feeders) — plants are autotrophs. Phototrophs gain energy from sunlight.
Chemotrophs obtain energy from chemical compounds. These terms can be combined: photoautotrophs use light energy and CO₂ carbon; chemoheterotrophs
(like humans) use chemical energy and organic carbon; photoheterotrophs use light energy and organic carbon; chemoautotrophs use chemical energy and CO₂.
, 4. Which of the following correctly classifies organisms by their energy and carbon sources?
A. Photoautotrophs — energy from chemicals, carbon from organic compounds
B. Chemoautotrophs — energy from chemical compounds, carbon from CO₂ (inorganic); example: methanogens
C. Photoheterotrophs — energy from chemicals, carbon from CO₂
D. Chemoheterotrophs — energy from sunlight, carbon from organic compounds
CORRECT ANSWER B — Chemoautotrophs — energy from chemical compounds, carbon from CO₂ (inorganic); example: methanogens
RATIONALE The four major nutritional categories are: (1) Photoautotrophs — energy from sunlight, carbon from CO₂ (plants, algae, cyanobacteria); (2) Photoheterotrophs —
energy from sunlight, carbon from organic compounds (green photosynthetic bacteria); (3) Chemoautotrophs — energy from chemical compounds, carbon from
CO₂ (methanogens, deep-sea vent bacteria); (4) Chemoheterotrophs — energy from chemical compounds, carbon from organic compounds (animals, many
bacteria). Humans are chemoheterotrophs. This classification system is based on two criteria: energy source and carbon source.
5. Using the mnemonic "Lazy Lions Sit Down," what are the four phases of the bacterial growth curve in order?
A. Log → Lag → Stationary → Death
B. Lag → Log (Exponential) → Stationary → Death
C. Stationary → Lag → Death → Log
D. Death → Stationary → Log → Lag
CORRECT ANSWER B — Lag → Log (Exponential) → Stationary → Death
RATIONALE The mnemonic "Lazy Lions Sit Down" represents the four phases: (1) Lag phase — adjustment period, little to no cell division; (2) Log (Exponential) phase — rapid
cell division and population growth, cells are most vulnerable to antibiotics; (3) Stationary phase — growth rate slows as nutrients deplete and waste accumulates,
population stabilizes; (4) Death phase — cells die at an exponential rate due to harsh conditions. Bacteria reproduce by binary fission. Understanding growth
phases is critical for infection treatment timing and food safety.
6. Mesophiles are microorganisms that thrive at moderate temperatures. What is their typical temperature range?
A. Below 0°C — they are psychrophiles
B. 10°C to 50°C — includes most human pathogens
C. Above 80°C — they are hyperthermophiles
D. Only at exactly 37°C — human body temperature
CORRECT ANSWER B — 10°C to 50°C — includes most human pathogens
RATIONALE Mesophiles thrive at moderate temperatures ranging from approximately 10°C to 50°C, with an optimum around 20–40°C. Most human pathogens are mesophiles
because the human body temperature (37°C) falls within this range. Psychrophiles grow at cold temperatures (optimum ~15°C). Psychrotolerant organisms can
grow at cold temps but prefer warmer ones (13–30°C). Thermophiles thrive above 45°C. Barophiles love hydrostatic pressure. Halophiles are salt-loving bacteria.
Understanding temperature requirements helps predict where organisms can grow and cause infection.
7. Which antimicrobial drug correctly matches its target mechanism of action?
A. Fluoroquinolones — target cell wall synthesis
B. Cephalosporin — targets cell wall synthesis
C. Tetracycline (broad spectrum) — targets DNA/RNA synthesis
D. Polymyxin (narrow spectrum) — targets folic acid synthesis
CORRECT ANSWER B — Cephalosporin — targets cell wall synthesis
RATIONALE The correct drug-target pairings are: Fluoroquinolones — target DNA/RNA synthesis; Polymyxin (narrow spectrum) — targets cell membrane; Cephalosporin —
targets cell wall synthesis; Tetracycline (broad spectrum) — targets protein synthesis; Trimethoprim — targets folic acid synthesis. Antibiotics are natural,
semisynthetic, or synthetic substances that target bacteria. Antimicrobial agents inhibit or kill microorganisms broadly. A bacteriostatic drug prevents growth and
reproduction but does not kill; a bactericidal drug kills bacteria directly. β-lactamase is an enzyme that breaks the β-lactam ring, inactivating penicillin.
8. Sterilization differs from disinfection and antisepsis in that sterilization:
A. Only removes pathogens from living tissue
B. Kills vegetative cells but not endospores on inanimate objects
C. Kills both vegetative cells AND endospores — examples include flame, oven, and autoclave
D. Only inhibits bacterial growth without killing
CORRECT ANSWER C — Kills both vegetative cells AND endospores — examples include flame, oven, and autoclave
RATIONALE Sterilization is the only process that kills both vegetative cells AND endospores — the most resistant microbial forms. Methods include flame, oven (dry heat), and
autoclave (steam under pressure). Disinfection is used on inanimate (nonliving) objects and kills vegetative cells but NOT endospores (e.g., chemicals, boiling
water). Antisepsis removes pathogens from living tissue and removes vegetative cells but not endospores. Antivirals inhibit virus growth and replication inside the
body. Exotoxins are proteins secreted by living bacterial cells; endotoxins are part of the outer membrane of Gram-negative bacteria and are not secreted.
2 MAXE • 242 SOIB
★ ★
C College of Nursing & Health Professions
J O U R N E Y T O E X T R A O R D I N A R Y CO M PA S S I O N AT E C A R E
EST. 1889
BIOS 242 — Examination 2
M I C R O B I A L N U T R I T I O N , G R O W T H , M E TA B O L I S M , CO N T R O L & I N F E C T I O N
INSTITUTION Chamberlain University COURSE CODE BIOS 242
PROGRAM Bachelor of Science in Nursing (BSN) ACADEMIC YEAR
EXAM TITLE Examination 2 — Fundamentals of Microbiology TOTAL QUESTIONS 25 Questions
COURSE TITLE Fundamentals of Microbiology FORMAT Multiple Choice — Select the Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question unless otherwise instructed.
▸ This examination covers microbial nutrition, growth phases, metabolism, control methods, antibiotic resistance, and infection stages.
▸ All content reflects BIOS 242 learning objectives and foundational microbiology for nursing practice.
▸ Correct answers and detailed rationales appear below each question for exam preparation purposes.
▸ Use mnemonics "Lazy Lions Sit Down" (growth phases) and "I Pat A Cat" (infection stages).
SECTION I — NUTRITION, GROWTH, METABOLISM, CONTROL, RESISTANCE & INFECTION Questions 1 – 25
1. Saprobes obtain nutrients and energy from which source?
A. Living host tissues and fluids — they are parasites
B. Dead or nonliving material — examples include fungi and bacteria
C. Sunlight through photosynthesis
D. Inorganic chemical compounds like rocks
CORRECT ANSWER B — Dead or nonliving material — examples include fungi and bacteria
RATIONALE Saprobes (saprophytes) obtain nutrients and energy from dead or nonliving organic material. They are decomposers that recycle nutrients in ecosystems — fungi
and many bacteria are saprobes. Parasites obtain nutrients from living host tissues/fluids (e.g., helminths). A mutualistic relationship benefits both organisms
(e.g., gut intestinal bacteria). This nutritional classification is based on the source of organic matter an organism uses. Understanding these ecological
relationships is fundamental to microbiology.
2. A facultative anaerobe is best described as an organism that:
A. Requires oxygen and will die without it
B. Cannot tolerate oxygen and will die if it is present
C. Prefers oxygen but can still multiply if oxygen is absent
D. Does not use oxygen at all in any circumstances
CORRECT ANSWER C — Prefers oxygen but can still multiply if oxygen is absent
RATIONALE A facultative anaerobe prefers oxygen for metabolism but can survive and multiply without it by switching to fermentation or anaerobic respiration. An aerobe
requires oxygen. An anaerobe does not use oxygen. An obligate anaerobe will die if oxygen is present. This flexibility allows facultative anaerobes to colonize
diverse environments. Many medically important bacteria (E. coli, Staphylococcus) are facultative anaerobes, which explains their ability to cause infections in
both oxygenated and oxygen-poor body sites.
3. Heterotrophs differ from autotrophs in that heterotrophs:
A. Use inorganic CO₂ to build their own organic molecules (self-feeders)
B. Must obtain carbon in organic form from other living things — examples include animals
C. Gain energy from sunlight through photosynthesis
D. Obtain energy exclusively from chemical compounds
CORRECT ANSWER B — Must obtain carbon in organic form from other living things — examples include animals
RATIONALE Heterotrophs must obtain their carbon in organic form — they are nutritionally dependent on other life forms. Examples include animals, fungi, and many
bacteria. Autotrophs use inorganic CO₂ to build their own organic molecules (self-feeders) — plants are autotrophs. Phototrophs gain energy from sunlight.
Chemotrophs obtain energy from chemical compounds. These terms can be combined: photoautotrophs use light energy and CO₂ carbon; chemoheterotrophs
(like humans) use chemical energy and organic carbon; photoheterotrophs use light energy and organic carbon; chemoautotrophs use chemical energy and CO₂.
, 4. Which of the following correctly classifies organisms by their energy and carbon sources?
A. Photoautotrophs — energy from chemicals, carbon from organic compounds
B. Chemoautotrophs — energy from chemical compounds, carbon from CO₂ (inorganic); example: methanogens
C. Photoheterotrophs — energy from chemicals, carbon from CO₂
D. Chemoheterotrophs — energy from sunlight, carbon from organic compounds
CORRECT ANSWER B — Chemoautotrophs — energy from chemical compounds, carbon from CO₂ (inorganic); example: methanogens
RATIONALE The four major nutritional categories are: (1) Photoautotrophs — energy from sunlight, carbon from CO₂ (plants, algae, cyanobacteria); (2) Photoheterotrophs —
energy from sunlight, carbon from organic compounds (green photosynthetic bacteria); (3) Chemoautotrophs — energy from chemical compounds, carbon from
CO₂ (methanogens, deep-sea vent bacteria); (4) Chemoheterotrophs — energy from chemical compounds, carbon from organic compounds (animals, many
bacteria). Humans are chemoheterotrophs. This classification system is based on two criteria: energy source and carbon source.
5. Using the mnemonic "Lazy Lions Sit Down," what are the four phases of the bacterial growth curve in order?
A. Log → Lag → Stationary → Death
B. Lag → Log (Exponential) → Stationary → Death
C. Stationary → Lag → Death → Log
D. Death → Stationary → Log → Lag
CORRECT ANSWER B — Lag → Log (Exponential) → Stationary → Death
RATIONALE The mnemonic "Lazy Lions Sit Down" represents the four phases: (1) Lag phase — adjustment period, little to no cell division; (2) Log (Exponential) phase — rapid
cell division and population growth, cells are most vulnerable to antibiotics; (3) Stationary phase — growth rate slows as nutrients deplete and waste accumulates,
population stabilizes; (4) Death phase — cells die at an exponential rate due to harsh conditions. Bacteria reproduce by binary fission. Understanding growth
phases is critical for infection treatment timing and food safety.
6. Mesophiles are microorganisms that thrive at moderate temperatures. What is their typical temperature range?
A. Below 0°C — they are psychrophiles
B. 10°C to 50°C — includes most human pathogens
C. Above 80°C — they are hyperthermophiles
D. Only at exactly 37°C — human body temperature
CORRECT ANSWER B — 10°C to 50°C — includes most human pathogens
RATIONALE Mesophiles thrive at moderate temperatures ranging from approximately 10°C to 50°C, with an optimum around 20–40°C. Most human pathogens are mesophiles
because the human body temperature (37°C) falls within this range. Psychrophiles grow at cold temperatures (optimum ~15°C). Psychrotolerant organisms can
grow at cold temps but prefer warmer ones (13–30°C). Thermophiles thrive above 45°C. Barophiles love hydrostatic pressure. Halophiles are salt-loving bacteria.
Understanding temperature requirements helps predict where organisms can grow and cause infection.
7. Which antimicrobial drug correctly matches its target mechanism of action?
A. Fluoroquinolones — target cell wall synthesis
B. Cephalosporin — targets cell wall synthesis
C. Tetracycline (broad spectrum) — targets DNA/RNA synthesis
D. Polymyxin (narrow spectrum) — targets folic acid synthesis
CORRECT ANSWER B — Cephalosporin — targets cell wall synthesis
RATIONALE The correct drug-target pairings are: Fluoroquinolones — target DNA/RNA synthesis; Polymyxin (narrow spectrum) — targets cell membrane; Cephalosporin —
targets cell wall synthesis; Tetracycline (broad spectrum) — targets protein synthesis; Trimethoprim — targets folic acid synthesis. Antibiotics are natural,
semisynthetic, or synthetic substances that target bacteria. Antimicrobial agents inhibit or kill microorganisms broadly. A bacteriostatic drug prevents growth and
reproduction but does not kill; a bactericidal drug kills bacteria directly. β-lactamase is an enzyme that breaks the β-lactam ring, inactivating penicillin.
8. Sterilization differs from disinfection and antisepsis in that sterilization:
A. Only removes pathogens from living tissue
B. Kills vegetative cells but not endospores on inanimate objects
C. Kills both vegetative cells AND endospores — examples include flame, oven, and autoclave
D. Only inhibits bacterial growth without killing
CORRECT ANSWER C — Kills both vegetative cells AND endospores — examples include flame, oven, and autoclave
RATIONALE Sterilization is the only process that kills both vegetative cells AND endospores — the most resistant microbial forms. Methods include flame, oven (dry heat), and
autoclave (steam under pressure). Disinfection is used on inanimate (nonliving) objects and kills vegetative cells but NOT endospores (e.g., chemicals, boiling
water). Antisepsis removes pathogens from living tissue and removes vegetative cells but not endospores. Antivirals inhibit virus growth and replication inside the
body. Exotoxins are proteins secreted by living bacterial cells; endotoxins are part of the outer membrane of Gram-negative bacteria and are not secreted.
