Multiple-Choice Questions (40 Questions)
,1. To survive, microbial inhabitants have learned to adapt by varying all of the following, except:
A) Growth rate
B) Growth in all atmospheric conditions
C) Growth at particular temperatures
D) Bacterial shape
Correct Answer: D
Rationale: Bacterial shape as a form of evolution is not discussed as an adaptive mechanism.
Microorganisms adapt through growth rate, atmospheric conditions, and temperature requirements .
2. Who was considered the father of protozoology and bacteriology?
A) Anton van Leeuwenhoek
B) Louis Pasteur
C) Carl Landsteiner
D) Michael Douglas
Correct Answer: A
Rationale: Anton van Leeuwenhoek was the inventor of the microscope and the first person to see
microorganisms ("beasties"). He is dubbed the father of protozoology and bacteriology .
3. Prokaryotic cells have which of the following structures in their cytoplasm?
A) Golgi apparatus
B) Ribosomes
C) Mitochondria
D) Endoplasmic reticulum
Correct Answer: B
Rationale: Ribosomes are the only structures listed that apply to prokaryotic cells; the others are found
in eukaryotic cells .
4. This form of DNA is commonly found in eukaryotic cells:
A) Linear
B) Circular
C) Plasmid
D) Colloid
Correct Answer: A
Rationale: Circular and plasmid DNA are usually found only in bacteria, not eukaryotic cells. Colloid is a
property of protein molecules and is not associated with nucleotides .
5. The nuclear membrane in prokaryotes is:
A) Missing
B) Impenetrable
C) A classic membrane
D) A lipid bilayer membrane
Correct Answer: A
Rationale: Prokaryotic cells do not have any membrane-bound structures in the cytoplasm, including a
structured nucleus .
6. A microorganism that is a unicellular organism and lacks a nuclear membrane and true nucleus
belongs to which classification?
,A) Fungi
B) Bacteria
C) Algae
D) Parasite
Correct Answer: B
Rationale: Fungi, algae, and parasites are eukaryotic organisms that contain a true nucleus. Bacteria are
prokaryotic and do not contain a true nucleus or nuclear membrane .
7. In the laboratory, the clinical microbiologist is responsible for all the following, except:
A) Isolating microorganisms
B) Selecting treatment for patients
C) Identifying microorganisms
D) Analyzing bacteria that cause disease
Correct Answer: B
Rationale: Clinical microbiologists do not select treatment for patients; they provide the physician with
organism identification and antibiotic susceptibility information .
8. What enables the microbiologist to select the correct media for primary culture and optimize the
chance of isolating a pathogenic organism?
A) Determining staining characteristics
B) Understanding the cell structure and biochemical pathways of an organism
C) Understanding the growth requirements of potential pathogens at specific body sites
D) Knowing the differences in cell walls of particular bacteria
Correct Answer: C
Rationale: By understanding growth requirements, a microbiologist can maximize the chance of isolating
an organism from a culture .
9. A clinical laboratory scientist notices that a culture has both a unicellular form and a filamentous
form. What type of organism exhibits these forms?
A) Virus
B) Fungi
C) Bacteria
D) Parasite
Correct Answer: B
Rationale: Fungi may have both unicellular yeast forms and filamentous hyphal forms in the same
culture plate .
10. All of the following statements are true about viruses, except:
A) Viruses consist of DNA or RNA but not both
B) Viruses are acellular but are surrounded by a protein coat
C) Viruses can infect bacteria, plants, and animals
D) Viruses do not need host cells to survive and grow
Correct Answer: D
Rationale: Viruses need host cells because they cannot reproduce or nourish themselves without the
host's cellular mechanisms .
, 11. Diagnostic microbiologists apply placement and naming of bacterial organisms into all the following
categories, except:
A) Order
B) Family
C) Genus
D) Species
Correct Answer: A
Rationale: Clinical microbiologists use family, genus, and species taxonomic categories to identify
species important for diagnostic diseases, not order .
12. Bacterial species that exhibit phenotypic differences are considered:
A) Biovarieties
B) Serovarieties
C) Phagevarieties
D) Subspecies
Correct Answer: A
Rationale: Biovarieties vary based on biochemical test results, serovarieties vary based on serologic test
results, and phagevarieties is a fictitious word .
13. What structure is described as a phospholipid bilayer embedded with proteins and sterols that
regulates the type and amount of chemicals that pass in and out of a cell?
A) Cell wall
B) Mitochondria
C) Endoplasmic reticulum
D) Plasma membrane
Correct Answer: D
Rationale: The plasma membrane is a phospholipid bilayer that regulates transport. The cell wall is the
outer covering; mitochondria are organelles; endoplasmic reticulum is where protein synthesis occurs .
14. What makes the interior of the plasma membrane potentially impermeable to water-soluble
molecules?
A) The hydrophobic tails of the phospholipid molecules are found there
B) The hydrophilic tails of the phospholipid molecules are found there
C) The ion channels are found there
D) The cholesterol molecules in the plasma membrane are found solely in the interior of the membrane
Correct Answer: A
Rationale: The hydrophobic tails of the phospholipid molecules face away from fluids and form the
interior of the plasma membrane, making it impermeable to water-soluble molecules .
15. The function of a cell wall is to:
A) Regulate the transport of macromolecules in and out of the cell
B) Provide rigidity and strength to the exterior of the cell
C) Provide reserve energy to the eukaryotic cell
D) Protect the eukaryotic from predators
Correct Answer: B