Deck 28: Microbiology

Question 1

Which of the following terms would describe a chain of rod-shaped bacterial cells?

A) staphylococcus
B) streptospirilli
C) diplobacilli
D) streptococcus
E) streptobacilli

Answer 1

E

Question 2

Which of the following describes the archaea?

A) methanogens
B) halophiles
C) thermoacidophiles
D) prokaryotes
E) All of the answer choices describe the archaea.

Answer 2

E

Question 3

Which of the following is considered to be acellular?

A) bacteria
B) fungi
C) algae
D) protozoans
E) viruses

Answer 3

E

Question 4

Which two domains do the prokaryotes belong?

A) Archaea and Cyanobacteria
B) Bacteria and Cyanobacteria
C) photosynthetic bacteria and chemosynthetic bacteria
D) Archaea and Bacteria
E) autotrophs and heterotrophs

Question 5

What differentiates Gram-positive and Gram-negative bacteria?

A) the type of DNA or RNA they contain
B) their ability or lack of ability to fix nitrogen
C) whether they are aerobic or anaerobic
D) whether their cell walls have a thin or thick layer of peptidoglycan
E) their specific rRNA sequences

Question 6

Which organisms form lichens?

A) archaea and algae
B) archaea and fungi
C) cyanobacteria and algae
D) cyanobacteria and fungi
E) cyanobacteria and archaea

Question 7

Which of the following is considered a method of horizontal gene transfer in bacteria?

A) binary fission only
B) transformation and binary fission
C) conjugation and budding
D) transduction and conjugation only
E) conjugation, transformation, and transduction

Question 8

Which statement is true about bacteria?

A) Bacteria contain a nucleus.
B) Bacteria lack ribosomes.
C) Bacteria usually lack a cell wall.
D) Bacteria only reproduce sexually.
E) Bacteria contain a single, circular chromosome.

Question 9

Which of the following describes the process of transformation?

A) crossing-over between paired chromosomes in meiosis
B) a bacteria cell passing DNA to another bacterial cell by means of a sex pilus
C) virus carries DNA from a previous host cell to a new host cell
D) live bacterium picks up DNA from a dead bacterium
E) one bacterial cell dividing to form two bacterial cells

Question 10

Which of the following is a true statement about bacteria?

A) Bacteria lack mitochondria.
B) Bacteria lack a nucleus but have DNA.
C) Bacteria occur in three basic shapes.
D) Bacteria have a single circular chromosome.
E) All of the answer choices are true statements about bacteria.

Question 11

Which statement is true about cyanobacteria?

A) They are sometimes erroneously called blue-green algae.
B) They can form toxic blooms in water enriched with nutrients.
C) They can combine with fungi to form lichens.
D) They can colonize rocks.
E) All of the answer choices are true statements about cyanobacteria.

Question 12

Which of the following associations is correct?

A) herpesvirus-chickenpox
B) Epstein-Barr virus-shingles
C) viroid-scrapie
D) prion-influenza
E) HIV-Creutzfeldt-Jakob disease

Question 13

One bacterial cell passes DNA to a second cell through a sex pilus in the process of

A) transformation.
B) transduction.
C) conjugation.
D) infection.
E) replication.

Question 14

A virus carries a piece of bacteria DNA from one bacterium to another in a process called

A) transformation.
B) transduction.
C) conjugation.
D) infection.
E) replication.

Question 15

Metabolically, archaea

A) are all photosynthetic.
B) are all heterotrophic.
C) can be heterotrophic or autotrophic.
D) are all parasitic.

Question 16

Which type of prokaryotes are able to live in the most extreme environments?

A) cyanobacteria
B) anaerobic bacteria
C) archaea
D) heterotrophic
E) aerobic bacteria

Question 17

Which type of organism will form endospores when faced with unfavorable environmental conditions?

A) viruses
B) bacteria
C) algae
D) protozoans
E) viroids

Question 18

Antibiotics are used to treat

A) viral infections.
B) bacterial infections.
C) viroid infections.
D) prion infections.
E) fungal infections.

Question 19

How are the archaea different from bacteria?

A) Archaea show the earliest form of photosynthetic ability.
B) Bacteria lack the peptidoglycan cell wall found in the archaea.
C) Archaea have a monolayer of lipids with branched side chains.
D) Archaea have evolved far more advanced forms of metabolism than bacteria.
E) Archaea have very delicate plasma membranes compared to more durable bacteria.

Question 20

Which relationship is correct?

A) halophiles-cold Antarctic ice
B) thermoacidophiles-hot, acidic environments
C) methanogens-high salt concentration
D) cyanobacteria-bacteriorhodopsin
E) methanogens-live in very high altitudes

Question 21

Which stage of viral reproduction takes place when the spikes of the virus bind to a specific receptor molecule on the surface of a host cell?

A) attachment stage
B) penetration stage
C) biosynthesis stage
D) maturation stage
E) release stage

Question 22

Naked strands of RNA not covered by a capsid are

A) archaea.
B) retroviruses.
C) viroids.
D) prions.
E) viruses.

Question 23

The core of a virus contains

A) a membranous envelope.
B) both DNA and RNA.
C) either DNA or RNA.
D) a protein capsid.
E) a protein spore coat.

Question 24

Which of the following is true about viruses?

A) The genome may be DNA or RNA.
B) The nucleic acid may be single or double stranded.
C) Viruses exhibit host specificity.
D) Viruses are obligate intracellular parasites.
E) All of the answer choices are true statements about viruses.

Question 25

Which of the following is a characteristic of bacteria but not viruses?

A) They are acellular.
B) They are obligate parasites.
C) They can be synthesized from chemicals in the laboratory.
D) They can contain DNA or RNA.
E) Diseases caused by them may be treatable with antibiotics.

Question 26

Most viruses are

A) much smaller than bacteria.
B) usually more than 1 micron long.
C) larger than protists.
D) immeasurable.
E) single celled.

Question 27

Antonie van Leeuwenhoek was a Dutch tradesman and scientist who is famous for inventing the microscope.

Question 28

Some viruses contain which of the following structures on their outer surface?

A) a membranous envelope composed of the host's plasma membrane
B) both DNA and RNA from the host
C) either DNA or RNA
D) a protein capsid
E) a protein spore coat

Question 29

In order to infect a cell, a virus must

A) inject its protein into the cell while the nucleic acid remains attached to the host cell surface.
B) have a special protein spike on its surface capsid that can interact with a receptor protein on the surface of the host cell.
C) actively burrow through the cell wall or cell membrane of the host cell to reach the cell's nucleus.
D) produce a special extension of its cytoplasm when it comes into contact with the appropriate host cell.
E) have enzymes to break down the cell wall or cell membrane of the host cell.

Question 30

If a virus is latent

A) it cannot be a retrovirus.
B) the viral genome is reproduced along with the host cell.
C) it must be a retrovirus.
D) it is gaining a new envelope via "budding."
E) it is easy to develop immunity against.

Question 31

Proteinaceous infectious particles that cause degenerative diseases of the nervous system in humans and other animals are called

A) archaeans.
B) prions.
C) cyanobacteria.
D) phages.
E) retroviruses.

Question 32

Just after entering a cell, a virus

A) begins assembling more viruses.
B) removes its envelope.
C) loses its protein capsid and the viral genome is exposed.
D) immediately integrates its nucleic acid genome into the host chromosomes.
E) begins its cycle, which always results in the death of the animal cell.

Question 33

Which of the following is a true statement about retroviruses?

A) they contain the enzyme reverse transcriptase
B) it is able to carry out transcription of RNA to DNA
C) viral DNA remains in the host genome
D) can be hidden from the host immune system
E) All of the answer choices are true statements about the retroviruses.

Question 34

When small mutations gradually change the surface antigens of a virus so that antibodies to the original virus become less effective, this is known as

A) an arms race.
B) antigenic escape.
C) antibody migration.
D) antigenic drift.
E) spike reassortment.

Question 35

The capsid of a virus is composed of

A) RNA.
B) protein.
C) DNA.
D) cellulose.
E) lipid.

Question 36

Which of these is the most accurate description of a virus?

A) a noncellular living organism
B) one of the smallest bacteria known
C) a member of the kingdom Virusae
D) an organism composed of only a few cells
E) chemical complexes of RNA or DNA protected by protein

Question 37

The life cycle stage of an animal virus during which a mature capsid forms around copies of the viral RNA genome is

A) budding.
B) attachment.
C) biosynthesis.
D) uncoating.
E) assembly.

Question 38

Which of the following groups has a membrane composed of a monolayer of lipids with branched side chains that helps some members of the group tolerate acid and heat?

A) archaea
B) bacteria
C) fungi
D) prions
E) viruses

Question 39

Bovine spongiform encephalopathy (BSE), or "mad cow disease," is caused by a(n)

A) archaean.
B) bacterium.
C) cyanobacterium.
D) prion.
E) virus.

Question 40

Which statement is true about prion diseases?

A) Prions are believed to cause Creutzfeldt-Jakob disease (CJD).
B) Prions are misshapen proteins that cause other proteins to change shape.
C) Mad cow disease (BSE) is spread by consumption of cattle feed contaminated with prions.
D) The buildup of these abnormal proteins cause a loss of neurons.
E) All of the answer choices are true statements about prions.

Question 41

In addition to his work with bacteria, Louis Pasteur also suggested that something even smaller than a bacterium was the cause of rabies. What did Louis Pasteur accomplish that furthered our understanding of viral diseases?

A) He was the first to discover that viruses could be based on RNA rather than DNA.
B) He developed a vaccine that he used to save a young boy that had contracted rabies.
C) He was the first to see a virus under a microscope.
D) He was the first to determine the life cycle of a virus.
E) He invented the microscope.

Question 42

Pathogenic bacteria are becoming increasingly deadly because

A) humans do not wash their hands frequently enough.
B) antibiotic resistance is becoming more and more common due to humans taking unnecessary antibiotics.
C) they pick up genes from humans, allowing them to fool human body cells into thinking that they are harmless.
D) humans lose their natural immunity to many pathogens through lack of exposure.
E) there is an increasing number of side effects from antibiotics.

Question 43

Which hypothesis suggests that both polypeptides and RNA arose at the same time?

A) Aleksandr Oparin's coacervate theory
B) Stanley Miller's chemical soup theory
C) Sidney Fox's protein-first hypothesis
D) Alexander Cairns-Smith's simultaneous evolution of polypeptides and RNA hypothesis
E) Darwin's original theory of evolution, as written in Origin of Species

Question 44

Which of the following molecules is thought to have been absent from the primitive reducing atmosphere of early Earth?

A) water vapor (H₂O)
B) methane (CH₄)
C) hydrogen (H₂)
D) oxygen (O₂)
E) nitrogen (N₂)

Question 45

Which of the following scientist(s) received a Nobel Prize in Chemistry for their discovery that RNA can be both a substrate and an enzyme?

A) A. I. Oparin
B) Stanley Miller
C) Sidney Fox
D) Graham Cairns-Smith
E) Thomas Cech and Sidney Altman

Question 46

The hypothesis that RNA and polypeptides evolved simultaneously was proposed by

A) Stanley Miller.
B) Alexander Cairns-Smith.
C) Charles Darwin.
D) Gunter Wachtershauser
E) Sidney Fox.

Question 47

Which genus of bacteria causes more diseases in humans than any other?

A) E. coli
B) Staphylococcus
C) Streptococcus
D) Mycobacterium
E) Clostridium

Question 48

Microbiology is the study of microbes. Which of the following is considered a microbe?

A) archae
B) protists
C) viroids
D) bacteria
E) All of the answer choices are microbes.

Question 49

Although microbes are often equated with pathogens, not all are pathogenic and some help humans maintain their health. Which of the following are synthesized by bacteria that live in the human intestine?

A) folic acid and vitamin B₁₂
B) insulin and vitamin K
C) lipids and folic acid
D) vitamin K and lipids
E) vitamins K and B₁₂

Question 50

Miller's laboratory experiments showed that

A) the first cell was probably made of nucleic acids.
B) it is possible to form protocells.
C) the primitive gases can react together to produce small organic molecules.
D) atmospheric pressure is required for life to begin.
E) the earth is approximately 4.5 billion years old.

Question 51

Bacteria cause diseases in humans when they

A) rearrange the genes of the host to code for specific virulence factors that determine the type and extent of the illness.
B) carry the same genes as the host organism, causing them to be indistinguishable from the host cell.
C) carry the genes that code for virulent factors, causing them to be harmful to humans.
D) carry genes that allow them to become symbiotes.
E) carry the genes of organisms like birds (bird flu) or pigs (swine flu).

Question 52

If the hypothesis that protocells arose in a "RNA world" is correct, which of the following would be necessary to shift to a "DNA world"?

A) an enzyme or reaction capable of converting ribose to deoxyribose in nucleotides
B) enzymes for reverse transcription of RNA into DNA
C) new enzymes to replicate the DNA
D) new enzymes for transcribing DNA back to RNA
E) All of the answer choices list enzymes that would be necessary for a shift from an RNA world to a DNA world.

Question 53

Which of the following forms of energy is thought to have been involved in the production of large organic molecules in the primitive reducing atmosphere?

A) radioactivity
B) electrical energy
C) heat
D) radiation from the sun
E) All of the answer choices describe forms of energy that could have contributed to the production of large organic molecules on early Earth.

Question 54

The protein-first hypothesis

A) is supported by the discovery that RNA can act as a catalyst.
B) is supported by the fact that RNA can act as a substrate and as an enzyme.
C) suggests it was an "RNA world" about 4 billion years ago.
D) suggests that only RNA was needed to progress to the formation of the first cells.
E) suggests that sophisticated enzymes with the ability to synthesize DNA and RNA arose first from small molecules provided by the ocean.

Question 55

Louis Pasteur conducted an experiment to answer the question of whether or not living things can arise spontaneously from nonliving materials. In this experiment, he used two flasks of sterile broth. What were the results of this experiment?

A) In the flask with the curved neck, no growth occurred. However, growth did occur in the flask that allowed outside air to enter, demonstrating that living things came from outside the sterile broth.
B) No growth occurred in either flask, demonstrating that sterile broth could not promote growth.
C) Both flasks showed growth, demonstrating that spontaneous generation does occur.
D) While both flasks showed growth, the flask with the curved neck showed a higher growth, demonstrating that spontaneous generation does not require air.
E) No growth occurred in either flask, demonstrating that sterilizing the broth removed its nutrients so growth could not occur regardless of whether or not life was present.

Question 56

The fact that a nucleic acid is a very complicated molecule suggests that

A) the RNA-first hypothesis is impossible.
B) the protein-first hypothesis is therefore the only plausible hypothesis.
C) sophisticated enzymes were not present or available to synthesize it.
D) no natural system could ever generate them.
E) RNA could not have arisen on its own by chance, but required enzymes to guide the synthesis of nucleotides and nucleic acids.

Question 57

Which of the following is the correct order, from simple to complex, showing the origin of life?

A) proteins → CH₄ and NH₃ → amino acids → C, H, O, N
B) C, H, O, N → CH₄ and NH₃ → amino acids → proteins
C) C, H, O, N → amino acids → proteins → CH₄ and NH₃
D) amino acids → proteins → C, H, O, N → CH₄ and NH₃
E) CH₄ and NH₃ → proteins → C, H, O, N → amino acids

Question 58

The synthesis of DNA or RNA from the organic soup would have been guided by the actions of enzymes in the

A) protein-first hypothesis.
B) RNA-first hypothesis.
C) clay-catalyst hypothesis.
D) DNA-first hypothesis.

Question 59

What form of energy did the electric spark in the Miller-Urey experiment simulate?

A) lightning
B) ultraviolet radiation
C) heat from volcanoes
D) falling water
E) sound

Question 60

Bacteria can be beneficial in which of the following ways?

A) They can be used to clean up an oil spill in a process called bioremediation.
B) They can be used in industry to generate products, particularly in food processing.
C) They are present on the skin and help crowd out harmful bacteria.
D) They function in wastewater purification to remove both organic and inorganic substances.
E) All of the answer choices describe ways that bacteria can be beneficial.

Question 61

The plasma membrane of archaea is composed of a phospholipid bilayer.

Question 62

Describe the steps in viral replication.

Question 63

Biological evolution (the evolution of living cells) differs from chemical evolution (the evolution of the molecules that make living cells) in that biological evolution would have been possible only after the development of

A) a membrane.
B) nucleic acids.
C) enzymes.
D) a metabolic pathway.
E) RNA and enzymes.

Question 64

What general feature defines an organism as a microbe?

A) generally require a microscope to be seen
B) multicellular
C) heterotrophic
D) sexual reproduction
E) use aerobic respiration for metabolism

Question 65

What feature enables the archaea to survive in harsh environments?

A) their plasma membranes and cell walls
B) their metabolism
C) the ability to form multicellular organisms
D) their reproductive capabilities
E) their nucleus

Question 66

Most bacteria are heterotrophs that require an outside source of organic compounds in the same way animals do.

Question 67

List the four stages that are thought to have led to the formation of the first cells.

Question 68

Which description best fits a chemoautotroph bacteria?

A) They reduce carbon dioxide to an organic compound by using energetic electrons derived from chemicals.
B) They reduce oxygen to an inorganic compound by using energetic electrons derived from chemicals.
C) They utilize photosynthesis to produce their own food.
D) They transfer electrons to sulfate, producing hydrogen sulfate.
E) All of the answer choices are descriptions of a chemoautotroph bacteria.

Question 69

Which of the following is a benefit of microbes?

A) break down organic molecules
B) Various microbes help protect us from harmful microbes.
C) aid in digestion
D) synthesize vitamins K and B₁₂
E) All of the answer choices are benefits of microbes.

Question 70

Which feature is lacking in the cell wall of archaea that will distinguish them from the bacteria?

A) peptidoglycan
B) phospholipids
C) proteins
D) polysaccharides
E) None of the answer choices are lacking in the cell walls of the archaea.

Question 71

One hypothesis suggests that protobionts were heterotrophs, organisms that synthesized organic molecules from inorganic molecules and nutrients.

Question 72

The central dogma of genetics states that DNA directs protein synthesis and that information flows from

A) protein → RNA → DNA.
B) protein → DNA → RNA.
C) RNA → protein → DNA.
D) RNA → DNA → protein.
E) DNA → RNA → protein.

Question 73

Liposomes are composed of

A) amino acids.
B) protein.
C) glucose.
D) lipids.
E) nucleic acid.

Question 74

Which of the following is a true statement about protobionts (protocells)?

A) They would have contained DNA as the genetic material.
B) They evolved after the first true cells.
C) They represent stage 3 in the evolution of life.
D) They would have contained only monomers.
E) The hydrophilic heads of the membrane would have pointed inwards, while the hydrophobic tails would have pointed outwards.