PORTAGE LEARNING
Bachelor of Science in Biology (BS)
BIOL 271 — Microbiology
Academic Year: 2026/2027
Module #2 Exam — Complete Question Bank
Portage Learning — Rigorous & Competency-Based
Question 1
What is the nature of the outer membrane of G- cells?
A. Another membrane-like structure plus LPS and porins
B. A layer of protein protecting the cell
C. Just a slime layer
D. Left over makeup still on after a date with a protozoan
CORRECT ANSWER A. Another membrane-like structure plus LPS and porins
Rationale
The outer membrane of Gram-negative cells is a bilayer structure containing
lipopolysaccharides (LPS), lipoproteins, and porins. Porins are proteins that form channels
allowing the entry of small molecules.
, Question 2
What is the fate of fermentation end products?
A. They are stored in granules as long term nutrients
B. They are incorporated into cell structures
C. They are excreted into the cell's environment
D. They are metabolized into ATP
E. They are auctioned on eBay
CORRECT ANSWER C. They are excreted into the cell's environment
Rationale
Fermentation end products (such as ethanol, lactic acid, and CO₂) are excreted into the
cell's environment. This prevents toxic accumulation and allows glycolysis to continue by
regenerating NAD⁺.
Question 3
How many net ATP per glucose does glycolysis pathway produce?
A. 2
B. 3
C. 8
D. 9
E. between 5 and 1294
CORRECT ANSWER A. 2
Rationale
Glycolysis produces 4 ATP but consumes 2 ATP in the investment phase. The net gain is 2
ATP per glucose molecule.
, Question 4
What is the cell wall made of?
A. Cellulose
B. Peptidoglycan
C. Chitin
D. Lipopolysaccharide
CORRECT ANSWER B. Peptidoglycan
Rationale
Bacterial cell walls are composed of peptidoglycan, a polymer of N-acetylglucosamine
(NAG) and N-acetylmuramic acid (NAM) crosslinked with short peptide chains.
Question 5
What is the periplasm and what's in it?
A. A structure outside the outer membrane that collects nutrients
B. The volume between the inner and outer membrane with enzymes and receptors
C. The space around the cell's DNA that prevents bad mutations
D. The material around the capsule that keeps it intact
CORRECT ANSWER
B. The volume between the inner and outer membrane with enzymes and
receptors
Rationale
The periplasm is the space between the inner (cytoplasmic) membrane and the outer
membrane in Gram-negative bacteria. It contains enzymes, receptors, and binding proteins
involved in nutrient acquisition and digestion.
, Question 6
What method of horizontal gene transfer in bacteria involves the direct cell to cell
contact between the live donor and the live recipient?
A. Transformation
B. Conjugation
C. Transduction
D. Transcription
CORRECT ANSWER B. Conjugation
Rationale
Conjugation is the method of horizontal gene transfer that requires direct cell-to-cell
contact between a live donor and a live recipient through a sex pilus. The donor transfers a
plasmid to the recipient.
Question 7
True or False: Bacteria have simultaneous transcription and translation.
A. True
B. False
CORRECT ANSWER A. True
Rationale
In bacteria, transcription and translation occur simultaneously because there is no nuclear
membrane separating the DNA from the ribosomes. This allows for rapid gene expression.
Bachelor of Science in Biology (BS)
BIOL 271 — Microbiology
Academic Year: 2026/2027
Module #2 Exam — Complete Question Bank
Portage Learning — Rigorous & Competency-Based
Question 1
What is the nature of the outer membrane of G- cells?
A. Another membrane-like structure plus LPS and porins
B. A layer of protein protecting the cell
C. Just a slime layer
D. Left over makeup still on after a date with a protozoan
CORRECT ANSWER A. Another membrane-like structure plus LPS and porins
Rationale
The outer membrane of Gram-negative cells is a bilayer structure containing
lipopolysaccharides (LPS), lipoproteins, and porins. Porins are proteins that form channels
allowing the entry of small molecules.
, Question 2
What is the fate of fermentation end products?
A. They are stored in granules as long term nutrients
B. They are incorporated into cell structures
C. They are excreted into the cell's environment
D. They are metabolized into ATP
E. They are auctioned on eBay
CORRECT ANSWER C. They are excreted into the cell's environment
Rationale
Fermentation end products (such as ethanol, lactic acid, and CO₂) are excreted into the
cell's environment. This prevents toxic accumulation and allows glycolysis to continue by
regenerating NAD⁺.
Question 3
How many net ATP per glucose does glycolysis pathway produce?
A. 2
B. 3
C. 8
D. 9
E. between 5 and 1294
CORRECT ANSWER A. 2
Rationale
Glycolysis produces 4 ATP but consumes 2 ATP in the investment phase. The net gain is 2
ATP per glucose molecule.
, Question 4
What is the cell wall made of?
A. Cellulose
B. Peptidoglycan
C. Chitin
D. Lipopolysaccharide
CORRECT ANSWER B. Peptidoglycan
Rationale
Bacterial cell walls are composed of peptidoglycan, a polymer of N-acetylglucosamine
(NAG) and N-acetylmuramic acid (NAM) crosslinked with short peptide chains.
Question 5
What is the periplasm and what's in it?
A. A structure outside the outer membrane that collects nutrients
B. The volume between the inner and outer membrane with enzymes and receptors
C. The space around the cell's DNA that prevents bad mutations
D. The material around the capsule that keeps it intact
CORRECT ANSWER
B. The volume between the inner and outer membrane with enzymes and
receptors
Rationale
The periplasm is the space between the inner (cytoplasmic) membrane and the outer
membrane in Gram-negative bacteria. It contains enzymes, receptors, and binding proteins
involved in nutrient acquisition and digestion.
, Question 6
What method of horizontal gene transfer in bacteria involves the direct cell to cell
contact between the live donor and the live recipient?
A. Transformation
B. Conjugation
C. Transduction
D. Transcription
CORRECT ANSWER B. Conjugation
Rationale
Conjugation is the method of horizontal gene transfer that requires direct cell-to-cell
contact between a live donor and a live recipient through a sex pilus. The donor transfers a
plasmid to the recipient.
Question 7
True or False: Bacteria have simultaneous transcription and translation.
A. True
B. False
CORRECT ANSWER A. True
Rationale
In bacteria, transcription and translation occur simultaneously because there is no nuclear
membrane separating the DNA from the ribosomes. This allows for rapid gene expression.
