BIO 250 Exam 1 V2 | BIO 250 Microbiology | Actual
Q&A with Rationale (BIO250 Exam 1) |
StraighterLine
1. Which individual is credited with definitively disproving the theory of spontaneous
generation using swan-necked flasks?
A. Louis Pasteur
B. Antoni van Leeuwenhoek
C. Robert Hooke
D. Robert Koch
Correct Answer: A
Explanation: Louis Pasteur used unique swan-necked flasks to show that air alone does
not create microbes. His design allowed air to enter but trapped dust and microbes in the
neck, keeping the broth sterile. This experiment provided the final evidence needed to
overturn the long-held belief in spontaneous generation.
2. Select all of the following structures or components that are typically found in a Gram-
negative cell wall environment but not in a Gram-positive one. (Select all that apply)
A. Outer membrane
B. Thick peptidoglycan layer
C. Lipopolysaccharide (LPS)
,D. Periplasm
E. Teichoic acids
F. Porin proteins
Correct Answer: A, C, D, F
Explanation: Gram-negative bacteria possess an outer membrane containing
lipopolysaccharides and porins, which are absent in Gram-positive cells. The periplasm is
the region between the inner and outer membranes where various metabolic processes
occur. In contrast, Gram-positive cells are characterized by a thick peptidoglycan layer and
the presence of teichoic acids.
3. Which of the following is the correct order of taxonomic hierarchy from the most broad to
the most specific?
A. Domain, Phylum, Kingdom, Class, Order, Family, Genus, Species
B. Species, Genus, Family, Order, Class, Phylum, Kingdom, Domain
C. Kingdom, Domain, Phylum, Order, Class, Family, Genus, Species
D. Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Correct Answer: D
Explanation: The standard biological classification system begins with the most inclusive
category, the Domain. It then proceeds through Kingdom, Phylum, Class, Order, Family, and
, Genus, ending at the most specific level, the Species. Remembering the mnemonic ‘Dear
King Philip Came Over For Good Soup’ can help identify this hierarchy.
4. Who was the first person to observe and describe live microorganisms, which he referred
to as ‘animalcules’?
A. Robert Hooke
B. Joseph Lister
C. Antoni van Leeuwenhoek
D. Edward Jenner
Correct Answer: C
Explanation: Antoni van Leeuwenhoek was a Dutch cloth merchant who developed high-
quality magnifying lenses. He was the first to document living bacteria and protozoa in
samples of rainwater and teeth scrapings. While Robert Hooke saw cells in cork,
Leeuwenhoek was the first to see the microbial world in motion.
5. The formal system for naming and classifying organisms was established by which
scientist?
A. Alexander Fleming
B. Ignaz Semmelweis
C. Robert Koch
D. Carolus Linnaeus
Q&A with Rationale (BIO250 Exam 1) |
StraighterLine
1. Which individual is credited with definitively disproving the theory of spontaneous
generation using swan-necked flasks?
A. Louis Pasteur
B. Antoni van Leeuwenhoek
C. Robert Hooke
D. Robert Koch
Correct Answer: A
Explanation: Louis Pasteur used unique swan-necked flasks to show that air alone does
not create microbes. His design allowed air to enter but trapped dust and microbes in the
neck, keeping the broth sterile. This experiment provided the final evidence needed to
overturn the long-held belief in spontaneous generation.
2. Select all of the following structures or components that are typically found in a Gram-
negative cell wall environment but not in a Gram-positive one. (Select all that apply)
A. Outer membrane
B. Thick peptidoglycan layer
C. Lipopolysaccharide (LPS)
,D. Periplasm
E. Teichoic acids
F. Porin proteins
Correct Answer: A, C, D, F
Explanation: Gram-negative bacteria possess an outer membrane containing
lipopolysaccharides and porins, which are absent in Gram-positive cells. The periplasm is
the region between the inner and outer membranes where various metabolic processes
occur. In contrast, Gram-positive cells are characterized by a thick peptidoglycan layer and
the presence of teichoic acids.
3. Which of the following is the correct order of taxonomic hierarchy from the most broad to
the most specific?
A. Domain, Phylum, Kingdom, Class, Order, Family, Genus, Species
B. Species, Genus, Family, Order, Class, Phylum, Kingdom, Domain
C. Kingdom, Domain, Phylum, Order, Class, Family, Genus, Species
D. Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Correct Answer: D
Explanation: The standard biological classification system begins with the most inclusive
category, the Domain. It then proceeds through Kingdom, Phylum, Class, Order, Family, and
, Genus, ending at the most specific level, the Species. Remembering the mnemonic ‘Dear
King Philip Came Over For Good Soup’ can help identify this hierarchy.
4. Who was the first person to observe and describe live microorganisms, which he referred
to as ‘animalcules’?
A. Robert Hooke
B. Joseph Lister
C. Antoni van Leeuwenhoek
D. Edward Jenner
Correct Answer: C
Explanation: Antoni van Leeuwenhoek was a Dutch cloth merchant who developed high-
quality magnifying lenses. He was the first to document living bacteria and protozoa in
samples of rainwater and teeth scrapings. While Robert Hooke saw cells in cork,
Leeuwenhoek was the first to see the microbial world in motion.
5. The formal system for naming and classifying organisms was established by which
scientist?
A. Alexander Fleming
B. Ignaz Semmelweis
C. Robert Koch
D. Carolus Linnaeus
