SFSU General
Microbiology Exam 1 Prep
with correct answers 2025
Which of the following is least likely to be considered as a microbe?
(A) a microscopic insect (B) a bacteriophage
(C) photosynthetic bacteria (D) halophilic archaea
(E) Mycobacterium tuberculosis - CORRECT ANSWER-microscopic insect
Eukaryotic cells differ from prokaryotic cells in that
(A) eukaryotic cells have more complex metabolism (B) eukaryotic cells are more
abundant
(C) only eukaryotic cells have cytoskeleton (D) eukaryotic cells are always larger
(E) transcription and translation cannot occur simultaneously in eukaryotes - CORRECT
ANSWER-eukaryotes have a complex metabolism
The smallest genomes (and the first ones sequenced) tend to be those of
(A) humans (B) bacteria
(C) archaea (D) viruses
(E) fungi - CORRECT ANSWER-Viruses
What is a metagenome?
(A) a list of gene sequences for all the metabolic genes in an organism
,(B) collective metabolic capabilities of a group of microbes
(C) the mutated genome of a metastatic cancer cell
(D) the proposed genome sequence of the last universal common ancestor of all life
(E) genome sequences from all the organisms in a particular environment - CORRECT
ANSWER-genome sequences from all organisms in a particular enviroment
Microbes have shaped human history by
(A) being the causative agents of human epidemics
(B) being involved in the production of certain food products
(C) playing essential roles in the geochemical cycling of many elements
(D) all of the above
(E) A and B only - CORRECT ANSWER-all that shiz
Which of the following individual first observed single-celled microbes?
(A) John Tyndall (B) Antoni van Leeuwenhoek
(C) Louis Pasteur (D) Robert Hooke
(E) Lazzaro Spallanzani - CORRECT ANSWER-Antoni van leewenhoek
Which of the following individual discovered the microbial basis of fermentation and later
used it to refute the idea of spontaneous generation?
(A) Florence Nightingale (B) Antoni van Leeuwenhoek
(C) Louis Pasteur (D) Robert Hooke
(E) Robert Koch - CORRECT ANSWER-Pasteur
Which of the following individual discovered the antibiotic penicillin?
(A) Robert Koch (B) Alexander Fleming
(C) Lazzaro Spallanzani (D) Joseph Lister
(E) Edward Jenner - CORRECT ANSWER-Fleming
Which of the following is a difference between antiseptics and antibiotics?
(A) Antiseptics kill microbial cells but antibiotics do not.
(B) Antibiotics kill microbial cells but antiseptics do not.
(C) Antibiotics may be taken internally but antiseptics cannot.
(D) Antiseptics can be taken internally but antibiotics cannot.
(E) none of the above - CORRECT ANSWER-antibiotics ingestied, antiseptics are
topical
According to the endosymbiosis theory, mitochondria evolved from ancient
(A) fungi (B) cyanobacteria
(C) proteobacteria (D) archaea
(E) respiring protists - CORRECT ANSWER-proteobacteria
Which of the following were critical for Carl Woese to develop the three-domain scheme
of classification?
(A) germ theory of disease (B) sequences of 16S rRNA
(C) advances in light microscopy (D) petri dishes for pure cultures
, (E) ultracentrifugation techniques - CORRECT ANSWER-sequences of 16S RNA
The genetic expression machinery of archaea is most similar to that of?
(A) monera (B) prokaryotes
(C) eukaryotes (D) bacteria
(E) mitochondria - CORRECT ANSWER-eukaryotes
A bacteriophage is
(A) a method bacteria use for feeding (B) a type of archaea
(C) a virus that infects eukaryotic cells (D) a virus that infects bacteria
(E) a bacterium that consume viruses - CORRECT ANSWER-virus that infects bacteria
Which of the following would allow a disease-causing microbe not to adhere to Koch's
postulates?
(A) The microbe is found in all patients with a particular disease but also in some
patients without the disease.
(B) The microbe can infect multiple different species, for example both humans and
rabbits.
(C) The microbe can be grown in pure culture.
(D) The microbe is a eukaryotic pathogen.
(E) The microbe can be killed by antiseptics. - CORRECT ANSWER-microbe in all
patients sick and healthy
Which of the following does NOT contain DNA or RNA?
(A) prokaryote (B) eukaryote
(C) virus (D) viroid
(E) prion - CORRECT ANSWER-prion.
Empty magnification occurs when
(A) a microscope without lenses is used.
(B) the size of an image increases with no increase in resolution.
(C) the size of an image increases with an increase in resolution.
(D) the resolution of an image increases while the size of the image decreases.
(E) the resolution of an image decreases while the size of the image remains the same.
- CORRECT ANSWER-you increase image size without resolution
Which of the following is closest to the resolution limit of a light microscope?
(A) 2x10-5 m (B) 2x10-6 m
(C) 2x10-7 m (D) 2x10-8 m
(E) 2x10-9 m - CORRECT ANSWER-2e-7
A specimen has a diameter of 2 μm. What is the minimum magnification that will allow a
human to resolve this object?
(A) 5X (B) 10X
(C) 50X (D) 100X
(E) 500X - CORRECT ANSWER-100x
Microbiology Exam 1 Prep
with correct answers 2025
Which of the following is least likely to be considered as a microbe?
(A) a microscopic insect (B) a bacteriophage
(C) photosynthetic bacteria (D) halophilic archaea
(E) Mycobacterium tuberculosis - CORRECT ANSWER-microscopic insect
Eukaryotic cells differ from prokaryotic cells in that
(A) eukaryotic cells have more complex metabolism (B) eukaryotic cells are more
abundant
(C) only eukaryotic cells have cytoskeleton (D) eukaryotic cells are always larger
(E) transcription and translation cannot occur simultaneously in eukaryotes - CORRECT
ANSWER-eukaryotes have a complex metabolism
The smallest genomes (and the first ones sequenced) tend to be those of
(A) humans (B) bacteria
(C) archaea (D) viruses
(E) fungi - CORRECT ANSWER-Viruses
What is a metagenome?
(A) a list of gene sequences for all the metabolic genes in an organism
,(B) collective metabolic capabilities of a group of microbes
(C) the mutated genome of a metastatic cancer cell
(D) the proposed genome sequence of the last universal common ancestor of all life
(E) genome sequences from all the organisms in a particular environment - CORRECT
ANSWER-genome sequences from all organisms in a particular enviroment
Microbes have shaped human history by
(A) being the causative agents of human epidemics
(B) being involved in the production of certain food products
(C) playing essential roles in the geochemical cycling of many elements
(D) all of the above
(E) A and B only - CORRECT ANSWER-all that shiz
Which of the following individual first observed single-celled microbes?
(A) John Tyndall (B) Antoni van Leeuwenhoek
(C) Louis Pasteur (D) Robert Hooke
(E) Lazzaro Spallanzani - CORRECT ANSWER-Antoni van leewenhoek
Which of the following individual discovered the microbial basis of fermentation and later
used it to refute the idea of spontaneous generation?
(A) Florence Nightingale (B) Antoni van Leeuwenhoek
(C) Louis Pasteur (D) Robert Hooke
(E) Robert Koch - CORRECT ANSWER-Pasteur
Which of the following individual discovered the antibiotic penicillin?
(A) Robert Koch (B) Alexander Fleming
(C) Lazzaro Spallanzani (D) Joseph Lister
(E) Edward Jenner - CORRECT ANSWER-Fleming
Which of the following is a difference between antiseptics and antibiotics?
(A) Antiseptics kill microbial cells but antibiotics do not.
(B) Antibiotics kill microbial cells but antiseptics do not.
(C) Antibiotics may be taken internally but antiseptics cannot.
(D) Antiseptics can be taken internally but antibiotics cannot.
(E) none of the above - CORRECT ANSWER-antibiotics ingestied, antiseptics are
topical
According to the endosymbiosis theory, mitochondria evolved from ancient
(A) fungi (B) cyanobacteria
(C) proteobacteria (D) archaea
(E) respiring protists - CORRECT ANSWER-proteobacteria
Which of the following were critical for Carl Woese to develop the three-domain scheme
of classification?
(A) germ theory of disease (B) sequences of 16S rRNA
(C) advances in light microscopy (D) petri dishes for pure cultures
, (E) ultracentrifugation techniques - CORRECT ANSWER-sequences of 16S RNA
The genetic expression machinery of archaea is most similar to that of?
(A) monera (B) prokaryotes
(C) eukaryotes (D) bacteria
(E) mitochondria - CORRECT ANSWER-eukaryotes
A bacteriophage is
(A) a method bacteria use for feeding (B) a type of archaea
(C) a virus that infects eukaryotic cells (D) a virus that infects bacteria
(E) a bacterium that consume viruses - CORRECT ANSWER-virus that infects bacteria
Which of the following would allow a disease-causing microbe not to adhere to Koch's
postulates?
(A) The microbe is found in all patients with a particular disease but also in some
patients without the disease.
(B) The microbe can infect multiple different species, for example both humans and
rabbits.
(C) The microbe can be grown in pure culture.
(D) The microbe is a eukaryotic pathogen.
(E) The microbe can be killed by antiseptics. - CORRECT ANSWER-microbe in all
patients sick and healthy
Which of the following does NOT contain DNA or RNA?
(A) prokaryote (B) eukaryote
(C) virus (D) viroid
(E) prion - CORRECT ANSWER-prion.
Empty magnification occurs when
(A) a microscope without lenses is used.
(B) the size of an image increases with no increase in resolution.
(C) the size of an image increases with an increase in resolution.
(D) the resolution of an image increases while the size of the image decreases.
(E) the resolution of an image decreases while the size of the image remains the same.
- CORRECT ANSWER-you increase image size without resolution
Which of the following is closest to the resolution limit of a light microscope?
(A) 2x10-5 m (B) 2x10-6 m
(C) 2x10-7 m (D) 2x10-8 m
(E) 2x10-9 m - CORRECT ANSWER-2e-7
A specimen has a diameter of 2 μm. What is the minimum magnification that will allow a
human to resolve this object?
(A) 5X (B) 10X
(C) 50X (D) 100X
(E) 500X - CORRECT ANSWER-100x
