Deck 28: Microbiology

Question 1

The Archaea include all of the following EXCEPT the

A) methanogens.
B) lichens.
C) halophiles.
D) thermoacidophiles.
E) prokaryotes.

Answer 1

B
Explanation: All of the terms listed describe one or more types of archaea except for lichens which are organisms that are a combination of algae and fungi.Bloom's

Question 2

Which relationship is NOT correct?

A) halobacteria-high salt concentration
B) thermoacidophiles-cold Antarctic ice
C) methanogens-swamps and marshes
D) cyanobacteria-photosynthesis
E) methanogens-biogas and greenhouse warming

Answer 2

B
Explanation: All of the relationships listed are correct except for thermoacidophile and the Antarctic. Thermoacidophiles would live in extremely hot and acidic environments such as the hot springs at Yellowstone National Park.Bloom's

Question 3

Which statement is NOT true about bacteria?

A) They lack mitochondria.
B) They lack a nucleus but contain DNA.
C) They reproduce sexually.
D) They occur in three basic shapes.
E) They have a single circular chromosome.

Answer 3

C
Explanation: Bacteria are single celled organisms; they do not have any membrane bound organelles including a nucleus. Their DNA is a single circular chromosome that is located in the cytoplasm of the cell. Bacteria are found in one of three shapes; bacilli (rod), cocci (spheres) and spirillium (curved). They reproduce asexually through binary fission.Bloom's

Question 4

Metabolically,the archaea are

A) photosynthetic.
B) not metabolically active.
C) heterotrophic and some are autotrophic as well.
D) parasitic.
E) all autotrophs.

Question 5

Which statement is NOT true about cyanobacteria?

A) They were formerly called blue-green algae.
B) They release sulfur during photosynthesis.
C) They can combine with fungi to form lichens.
D) They are eukaryotic like fungi.
E) They can colonize rocks.

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 statement is true about bacteria?

A) They contain a nucleus.
B) They lack ribosomes.
C) They usually lack a cell wall.
D) They divide sexually.
E) They contain a single, circular DNA molecule as the genetic material.

Question 8

Which type of sexual exchange occurs among bacteria in which DNA is carried into a bacterial cell by means of a bacteriophage?

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

Question 9

Bacterial cells pick up free pieces of DNA from the medium-pieces that were released from dead bacteria-in a process called

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

Question 10

The three shapes of bacteria are

A) haplontic, diplontic, and alternations.
B) anaerobic, aerobic, and facultative.
C) heterotrophic, autotrophic, and chemosynthetic.
D) bacillus, coccus, and spirillum.
E) helical, spiral, and streptococci.

Question 11

Which of the following associations is correct?

A) herpesvirus - chicken pox
B) Streptococcus pyogenes - measles
C) trypanosome - Chlamydia
D) mycoses - Entamoeba
E) tinea - fungi

Question 12

Which of these is a correct description of a form of genetic recombination in bacteria?

A) Crossing-over occurs between paired chromosomes in meiosis.
B) Conjugation occurs when a cell passes DNA to another cell by means of a sex pilus.
C) Transformation occurs when a bacteriophage carries a bit of DNA from a previous host cell to a new host cell.
D) Transduction occurs when a live bacterium picks up DNA from dead bacteria that have shed it into the environment of the living cell.
E) Binary fission occurs when two bacteria cells exchange genetic information.

Question 13

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

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

Question 14

To be an effective antibiotic or chemotherapeutic agent,it is necessary

A) not to kill the human host or cause allergic reactions.
B) to be able to kill a bacterial cell only.
C) not to kill the human host or cause allergic reactions AND to be able to kill a bacterial cell only.
D) to change the genome of the bacterial disease agent.
E) to stop any universal living cell process.

Question 15

What is the evolutionary relationship among Archaea,Bacteria,and Eukarya?

A) Since Archaea are the most primitive, Archaean ancestors gave rise to bacteria that in turn gave rise to eukaryotes.
B) All three domains are equally distant from the most primitive common ancestor, a protocell.
C) Archaea and Eukarya share nucleic acid similarities so Eukarya split off from Archaea.
D) Bacterial ancestors gave rise to both Archaea and to eukaryotes as two separate side branches.
E) Archaea ancestors gave rise to both bacteria and to eukaryotes as two separate side branches.

Question 16

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

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

Question 17

A new classification by domains separates traditional bacteria into

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

Question 18

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 19

The response of bacteria that allows them to be identified as Gram-positive or negative is due to

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) the rRNA sequences they demonstrate.

Question 20

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) The Archaea have evolved far more advanced forms of metabolism than bacteria.
E) Archaea have very delicate plasma membranes compared to more durable bacteria.

Question 21

If a virus is latent,it

A) cannot be a retrovirus.
B) has integrated itself into the host cell genome.
C) must be a retrovirus.
D) is gaining a new envelope via "budding."
E) is easy to develop immunity against.

Question 22

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 on its surface capsid that can interact with a 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 23

Which statement is NOT true about a retrovirus?

A) It contains a DNA genome.
B) It contains the enzyme reverse transcriptase.
C) It is able to carry out transcription of RNA to DNA.
D) Viral DNA remains in the host genome.
E) Can be hidden from the host immune system.

Question 24

Which of the following is NOT a characteristic of a virus?

A) acellular
B) obligate parasite
C) can be synthesized from chemicals in the laboratory
D) diseases caused by viruses can be treated with antibiotics
E) contain DNA or RNA

Question 25

Which of the following is NOT true about viruses?

A) The genome may be DNA or RNA.
B) The nucleic acid may be single or double stranded.
C) They contain nucleic acid, protein, and mitochondria.
D) They exhibit host specificity.
E) They are obligate intracellular parasites.

Question 26

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

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

Question 27

Which of the following is considered to be noncellular?

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

Question 28

Naked strands of RNA not covered by a capsid are

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

Question 29

When an enveloped animal virus enters a cell,then

A) the next thing it does is assemble a new virus.
B) the envelope is removed after the virus is inside the cell's nucleus.
C) the protein capsid is removed through uncoating to expose the viral genome.
D) it immediately integrates its nucleic acid genome into the host chromosomes.
E) its cycle always results in the death of the animal cell.

Question 30

Some,but not all,viruses contain ______,located 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 31

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

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

Question 32

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) a cell at the boundary between living and nonliving things
E) chemical complexes of RNA or DNA protected by protein

Question 33

The innermost core of a virus's structure is made up of

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

Question 34

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 35

Viruses are

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

Question 36

Which group does NOT have members that cause human disease?

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

Question 37

Some human diseases appear to be due to protein agents that may convert other proteins in the cell to also become these agents; this new disease protein agent is called a(n)

A) archeon.
B) prion.
C) cyanobacterium.
D) phage.
E) retrovirus.

Question 38

Influenza strains that sweep around the world often carry names such as Shanghai H₁N₁ or Mexico City H₂N₂.The viruses vary in H and N surface spikes because

A) the viruses reproduce on their own and attack people in cities more often.
B) these viruses emerged as stray DNA from the genomes of people in these cities.
C) this is where the antibodies of immune people began to break down and the old virus was again virulent.
D) infected people develop immunity to the present strain, and strains that mutate sufficiently to be outside the range of immunity are soon spread in highly populated areas.
E) the H and N surface spikes are obtained from the human hosts.

Question 39

Which statement is NOT true about prion diseases?

A) Prions are believed to cause Creutzfeldt-Jakob disease (CJD).
B) Prions lack a nucleus but must form DNA/RNA at some time in order to replicate.
C) Prions are misshapen proteins that cause other proteins to change shape.
D) Mad cow disease (BSE) is spread by consumption of cattle feed contaminated with prions.
E) The build up of these abnormal proteins causes a loss of neurons.

Question 40

The capsid of a virus is composed of

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

Question 41

Microbiology is the study of microbes,these include all but which of the following?

A) Archae
B) Protists
C) Viroids
D) Plants
E) Fungi

Question 42

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

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

Question 43

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.How could this demonstrate the invalidity of spontaneous generation?

A) In the flask in which no outside materials could enter, no growth occurred while growth did occur in the flask that allowed outside air to enter demonstrating that the 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 that did not allow air to enter showed a higher growth demonstrating that while spontaneous generation does not occur that it does not take air to permit growth.
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 44

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 45

If oxygen had been present in the original primitive atmosphere,

A) organic molecules would be prevented from joining together.
B) microspheres could have formed.
C) aerobic cellular respiration would occur.
D) protocells would be able to form.
E) organisms could have carried out cellular respiration.

Question 46

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

A) proteins $\rarr$ CH₄ and NH₃ $\rarr$ amino acids $\rarr$ C, H, O, N
B) C, H, O, N $\rarr$ CH₄ and NH₃ $\rarr$ amino acid $\rarr$ proteins
C) C, H, O, N $\rarr$ amino acids $\rarr$ proteins $\rarr$ CH₄ and NH₃
D) amino acids $\rarr$ proteins $\rarr$ C, H, O, N $\rarr$ CH₄ and NH₃
E) CH₄ and NH₃ $\rarr$ proteins $\rarr$ C, H, O, N $\rarr$ amino acids

Question 47

The hypothesis that suggests that RNA and polypeptides might have evolved simultaneously was proposed by

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

Question 48

In addition to his work with bacteria,Louis Pasteur was also the one to name viruses.His work with rabies produced what breakthrough?

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 on a young rabies patient.
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 49

The organic soup in which the first cell is believed to have arisen probably contained

A) isolated atoms.
B) bubbling hot gases only.
C) algae and other microscopic organisms.
D) amino and organic acids.
E) nucleic acids and proteins.

Question 50

Although microbes are often equated with pathogens not all are pathogenic and some help humans maintain their health.Which of the following are produced 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 51

Bacteria cause diseases in humans when they

A) Carry genes that 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 of viruses causing them to be more harmful to humans.
D) Carry the genes of organisms like birds (bird flu) or pigs (swine flu).
E) Carry genes that allow them to become symbiotes.

Question 52

Antonie van Leeuwenhoek was a Dutch tradesman and scientist who is famous for all but one of the following.Which is the exception?

A) He thought that animals were able to arise spontaneously from inorganic sources.
B) He was skilled at grinding glass and made improvements in the microscope.
C) He was the first to see living organisms in a drop of water.
D) He invented the microscope.
E) He called the organisms that he saw in a drop of water 'wee animals'.

Question 53

Considering the various theories,the energy used in forming organic molecules in the primitive atmosphere could have come from all EXCEPT

A) lightning.
B) ultraviolet radiation.
C) heat from volcanoes.
D) electric spark.
E) sound.

Question 54

Which of the following forms of energy is NOT one of those 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) sound

Question 55

Bacteria can be beneficial in all but which of the following ways?

A) They can be used to clean up 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 are the primary producers of most ecosystems.
E) They function in waste water purification to remove both organic and inorganic substances.

Question 56

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

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

Question 57

If the hypothesis that protocells were based on an "RNA world" is correct,which would NOT 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) the presence of oxygen

Question 58

Pathogenic bacteria are becoming increasingly deadly as

A) Humans refuse to wash their hands frequently enough.
B) Antibiotic resistance builds when more and more humans take 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 are an increasing number of side effects from antibiotics.

Question 59

__________ showed that amino acids can polymerize abiotically when exposed to dry heat.

A)I. Oparin
B) Stanley Miller
C) Sidney Fox
D) Graham Cairns-Smith

Question 60

Which statement is NOT true about the RNA-first hypothesis?

A) It is supported by the discovery that RNA can act as a catalyst.
B) It is supported by the fact that RNA can act as a substrate and as an enzyme.
C) It suggests that there was an "RNA world" about 4 billion years ago.
D) It says that first RNA, then DNA, then proteins would have been necessary to interact in the chemical evolution that would have led to the development of the first cells.
E) It suggests that only RNA was needed to progress to the formation of the first cells.

Question 61

According to Fox's laboratory experiments,the protocell could have been composed

A) only of carbohydrates.
B) mostly of polypeptides.
C) of phospholipids.
D) of chitinous threads.
E) of protein and RNA.

Question 62

In a liquid environment,____ molecules will automatically form droplets called liposomes.

A) amino acid
B) protein
C) glucose
D) phospholipid
E) nucleic acid

Question 63

The first cell is believed to have carried on anaerobic respiration.This means that it would have

A) also carried on aerobic respiration.
B) given off oxygen.
C) carried on fermentation.
D) been parasitic.
E) been saprophytic.

Question 64

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) true cells.
B) nucleic acids.
C) enzymes.
D) a metabolic pathway.
E) RNA and enzymes.

Question 65

A complex protein-rich cell shelters and supports the DNA genetic code,and the code is the blueprint for the cell proteins; thus is set the "chicken-or-the-egg" dilemma of which came first.This is probably solved by the discovery that

A) polypeptides and RNA could have evolved simultaneously.
B) reverse transcriptase can convert RNA back into DNA.
C) all DNA and protein can be distributed evenly inside and outside the nucleus.
D) some proteins are simply assemblages of guanine, cytosine, thymine, and adenine.
E) viruses can give rise to all of the cell molecules.

Question 66

Which theory would suggest 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.
E) Darwin's original theory of evolution as written in Origin of Species.

Question 67

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) chloroplast.
E) DNA-first hypothesis.

Question 68

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 these features are lacking in the cell walls of the Archaea.

Question 69

Which term does NOT apply to the first protocell?

A) fermentation
B) autotrophic
C) membrane-bound
D) single-celled
E) self-replicating

Question 70

What feature enables the Archaea to survive in harsh environments?

A) Their cell walls.
B) Their nucleus.
C) Their metabolism.
D) The ability to form multicellular organisms.
E) Their reproductive capabilities.

Question 71

Which of these would have been most likely to develop only after the formation of a true cell?

A) autotroph
B) heterotroph
C) protocell
D) microsphere
E) proteinoid

Question 72

Which of the following is a benefit of microbes?

A) All of these are benefits of microbes.
B) Various microbes help protect us from harmful microbes.
C) Aid in digestion.
D) Synthesize vitamin K an vitamin B₁₂.
E) Breakdown organic molecules.

Question 73

Through molecular interaction of the macromolecules in the primitive ocean,the self-replicating system of ____ evolved.

A) protein $\rarr$ RNA $\rarr$ DNA
B) protein $\rarr$ DNA $\rarr$ RNA
C) RNA $\rarr$ protein $\rarr$ DNA
D) RNA $\rarr$ DNA $\rarr$ protein
E) DNA $\rarr$ RNA $\rarr$ protein

Question 74

Compare the Domains of Archaea and Eukarya in regards to their features.

Question 75

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 76

Which statement is NOT true about a protocell?

A) It would have contained DNA as its genetic material.
B) It would have been present before the development of a true cell.
C) It would have had a lipid and protein membrane surrounding it.
D) It would have contained a biochemical pathway for energy metabolism.
E) It might have been like a coacervate droplet in which a semipermeable boundary allows some materials to be absorbed from the surrounding environment.

Question 77

Which type of nutrition is believed to have come first?

A) autotrophic
B) heterotrophic
C) aerobic
D) photosynthetic
E) catalytic

Question 78

What general feature is necessary to consider an organism a microbe?

A) Small enough that a microscope is required to see them.
B) Multicellular.
C) Heterotrophic.
D) Sexual reproduction.
E) Use aerobic respiration for metabolism.

Question 79

Which of the following organisms is considered a microbe?

A) bacteria
B) snail
C) eagle
D) oak tree
E) roundworm

Question 80

Some twentieth-century authors wrote that the earliest protocells would have to be autotrophs.This concept appears to be

A) correct, since heterotrophs would depend upon eating autotrophs.
B) correct, since life is not possible without ATP which is only available in living systems.
C) correct, since glycolysis and fermentation only occur after oxygen is present from photosynthesis.
D) incorrect, since the primordial soup could contain many preformed food molecules.
E) incorrect, since glycolysis and fermentation require complex enzymes for catalytic reactions.