WGU D311 PRE-ASSESSMENT: MICROBIOLOGY WITH LAB: A
FUNDAMENTAL APPROACH (GMO1) (PGMO) UPDATED 2026
QUESTIONS AND ANSWERS 100% CORRECT
**1.** A microbiology student examines a specimen using a microscope
and notices that the organism contains genetic material enclosed within
a membrane-bound nucleus. Which classification BEST describes this
organism?
A. Prokaryote
B. Eukaryote
C. Virus
D. Prion
**Answer: B**
**2.** A bacterial cell is placed into an environment containing a high
concentration of solutes outside the cell. Water begins moving out of
the cell across the plasma membrane. Which process explains this
movement?
A. Diffusion
B. Facilitated diffusion
,C. Osmosis
D. Active transport
**Answer: C**
**3.** A bacterial species is classified as Gram-positive after staining.
Which structural characteristic MOST directly explains its ability to
retain the crystal violet-iodine complex during Gram staining?
A. A thick peptidoglycan layer in the cell wall
B. An outer membrane containing lipopolysaccharide
C. A capsule composed entirely of phospholipids
D. A thin peptidoglycan layer surrounding an outer membrane
**Answer: A**
**4.** During Gram staining, a student accidentally leaves the
decolorizing agent on the bacterial smear for too long. What is the
MOST likely consequence?
A. Gram-negative cells may appear falsely Gram-positive
B. Gram-positive cells may appear falsely Gram-negative
C. All bacteria will retain the primary stain
,D. The counterstain will become unnecessary
**Answer: B**
**5.** A microbiologist wants to isolate individual bacterial species
from a mixed culture. Which technique is MOST appropriate for
obtaining isolated colonies?
A. Streak plate technique
B. Simple staining
C. Gram staining
D. Capsule staining
**Answer: A**
**6.** A bacterial culture initially contains a small population of
organisms. Under favorable conditions, the population increases
exponentially through repeated cell division. Which phase of bacterial
growth is characterized by rapid reproduction?
A. Lag phase
B. Log phase
C. Stationary phase
, D. Death phase
**Answer: B**
**7.** A bacterial population reaches a point where nutrients become
limited and metabolic waste accumulates, causing the rate of cell
division to approximately equal the rate of cell death. Which growth
phase is occurring?
A. Lag phase
B. Log phase
C. Stationary phase
D. Exponential recovery phase
**Answer: C**
**8.** A microbiologist wants to determine whether an unknown
bacterium can metabolize lactose and produce acid. Which type of
laboratory procedure would BEST answer this question?
A. A biochemical test designed to detect lactose fermentation
B. A Gram stain alone
C. An endospore stain alone
FUNDAMENTAL APPROACH (GMO1) (PGMO) UPDATED 2026
QUESTIONS AND ANSWERS 100% CORRECT
**1.** A microbiology student examines a specimen using a microscope
and notices that the organism contains genetic material enclosed within
a membrane-bound nucleus. Which classification BEST describes this
organism?
A. Prokaryote
B. Eukaryote
C. Virus
D. Prion
**Answer: B**
**2.** A bacterial cell is placed into an environment containing a high
concentration of solutes outside the cell. Water begins moving out of
the cell across the plasma membrane. Which process explains this
movement?
A. Diffusion
B. Facilitated diffusion
,C. Osmosis
D. Active transport
**Answer: C**
**3.** A bacterial species is classified as Gram-positive after staining.
Which structural characteristic MOST directly explains its ability to
retain the crystal violet-iodine complex during Gram staining?
A. A thick peptidoglycan layer in the cell wall
B. An outer membrane containing lipopolysaccharide
C. A capsule composed entirely of phospholipids
D. A thin peptidoglycan layer surrounding an outer membrane
**Answer: A**
**4.** During Gram staining, a student accidentally leaves the
decolorizing agent on the bacterial smear for too long. What is the
MOST likely consequence?
A. Gram-negative cells may appear falsely Gram-positive
B. Gram-positive cells may appear falsely Gram-negative
C. All bacteria will retain the primary stain
,D. The counterstain will become unnecessary
**Answer: B**
**5.** A microbiologist wants to isolate individual bacterial species
from a mixed culture. Which technique is MOST appropriate for
obtaining isolated colonies?
A. Streak plate technique
B. Simple staining
C. Gram staining
D. Capsule staining
**Answer: A**
**6.** A bacterial culture initially contains a small population of
organisms. Under favorable conditions, the population increases
exponentially through repeated cell division. Which phase of bacterial
growth is characterized by rapid reproduction?
A. Lag phase
B. Log phase
C. Stationary phase
, D. Death phase
**Answer: B**
**7.** A bacterial population reaches a point where nutrients become
limited and metabolic waste accumulates, causing the rate of cell
division to approximately equal the rate of cell death. Which growth
phase is occurring?
A. Lag phase
B. Log phase
C. Stationary phase
D. Exponential recovery phase
**Answer: C**
**8.** A microbiologist wants to determine whether an unknown
bacterium can metabolize lactose and produce acid. Which type of
laboratory procedure would BEST answer this question?
A. A biochemical test designed to detect lactose fermentation
B. A Gram stain alone
C. An endospore stain alone
