Deck 20: Viruses, Bacteria, and Archaea

Question 1

A virus that follows the lysogenic cycle can often be considered easier to manage. Explain why this is so.

Answer 1

Answers may vary. Lysogenic viruses are ones that will attack the host cell in a relatively short time frame after the infection. The host will become aware that they have the virus and can seek treatment. A lytic virus can "hide" within the host cells and not make their appearance for quite some time. This is a type of virus that can go latent and not be expressed. It will incorporate the viral DNA into the host's DNA.

Question 2

If a virus is latent, it

A) cannot be a retrovirus.
B) is not actively replicating.
C) has not entered a lysogenic cycle.
D) is gaining a new envelope via "budding."
E) is easy to develop immunity against it.

Answer 2

B

Question 3

The cycle of viral infection in which the viral DNA is integrated into the host's DNA is called the _______ cycle.

A) lysogenic
B) lysozyme
C) lytic
D) lysol
E) lysosome

Answer 3

A

Question 4

Pasteur chose the Latin root word for "virus" meaning

A) extremely small.
B) non-living.
C) poison.
D) contagious.
E) particle.

Question 5

Which of the following could be used to grow lysogenic viruses in the laboratory?

A) chicken eggs
B) cell culture
C) bacteria
D) All of the choices could be used.

Question 6

Which statement is NOT true about a retrovirus?

A) It may cause cancer or AIDS.
B) It contains reverse transcriptase.
C) It remains in the host cell genome, but is not replicated when host DNA is replicated.
D) It has the capacity to integrate cDNA into the host DNA of the cell it infects.

Question 7

Many microbiologists prefer to describe viruses as being "activated" rather than "living." Consider again the discussion of "properties of life" and describe at least three distinct reasons why the term "activated" is more appropriate.

Question 8

Which of the following is not part of the reproduction cycle of HIV?

A) Reverse transcription of the viral RNA
B) Reverse transcription of the viral DNA
C) Maturation of the viruses
D) Biosynthesis of the viral mRNA

Question 9

An enveloped virus enters a host cell by

A) injecting its DNA or RNA into the host cell.
B) fusion of its envelope with the host cell's plasma envelope.
C) endocytosis.
D) Any of the choices are correct.
E) Attaching to the host cell's membrane and then injecting its DNA or RNA into the host cell.

Question 10

Which of these is the best 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 shell

Question 11

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 proteins because

A) the viruses reproduce 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) when infected people develop immunity to the present virus, strains that mutate sufficiently to be outside the range of immunity are soon spread in highly populated areas.

Question 12

What is the correct sequence of events in the lytic cycle of a bacteriophage infection?

A) Attachment, Viral DNA penetration into host cell, Integration of viral DNA into host cell DNA, Biosythesis, Maturation, Release
B) Endocytosis of virion, Uncoating, Maturation, and Release
C) Attachment, Fusion of envelope and host cell membrane, Biosynthesis, Maturation, and Release
D) Attachment, Viral DNA penetration, Biosynthesis, Maturation and Release

Question 13

Describe the lysogenic cycle of a bacteriophage and/or a prophage. Why do you think it would be useful to the virus to have this cycle.

Question 14

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 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.

Question 15

Viruses are categorized according to all of the following EXCEPT

A) size and shape.
B) their type of nucleic acid.
C) the presence of absence of an envelope.
D) their method of reproduction, whether asexual or sexual.

Question 16

Some, but not all, virus capsids are surrounded by _________.

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

Question 17

The cycle of viral infection of a bacterial cell that will cause its death most rapidly is called the _______ cycle.

A) lysogenic
B) lysozyme
C) lytic
D) lysol
E) lysosome

Question 18

Ivanowsky first recognized that something smaller than a bacterium, called a filterable virus, was able to cause disease in the year

A) 1965.
B) 2001.
C) 1892.
D) 1700.
E) 1650.

Question 19

What are the two Domains that the prokaryotes are classified under?

A) Archaea & Bacteria
B) Eukarya & Bacteria
C) Archaea & Eukarya
D) Protista & Archaea

Question 20

The innermost portion of a virus' structure is made up of

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

Question 21

Name the labeled structures of the virus pictured in this figure.
A: _____________
B: _____________
C: _____________
D: _____________
E: _____________ (protein shell)

Question 22

Prokaryotes generally range in size from

A) 10-400 nm.
B) 20-300 mm.
C) 10-100 µm.
D) 1-10 µm.
E) 50-100nm.

Question 23

Imagine a researcher is trying to genetically engineer this virus so it attacks the lung cells of a human in order to "infect" the host with a particular gene to cure a genetic disorder. Explain which structure the researcher would be most interested in working with in order to get the virus to attack the lung cell of a human.

Question 24

All of the following are means of genetic recombination in prokaryotes EXCEPT

A) conjugation.
B) transformation.
C) transduction.
D) crossing over.

Question 25

Prokaryotes are now divided into the

A) archaea and bacteria.
B) bacteria and cyanobacteria.
C) photosynthetic bacteria and chemosynthetic bacteria.
D) archaea and cyanobacteria.
E) autotrophs and heterotrophs.

Question 26

Bacteriophages carry portions of bacterial DNA from one cell to another in a process called

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

Question 27

All of the following are true of methanogens EXCEPT

A) they produce methane from CO₂ and H₂.
B) they live in the intestinal tracts of cows, humans, and termites.
C) they live in swamps and marshes.
D) their biogas may contribute to global warming.
E) they are harmful human pathogens.

Question 28

Similarities between the archaea and eukarya include

A) same ribosomal proteins.
B) similar tRNA.
C) similar initiation of transcription.
D) All of the choices are correct similarities.
E) are closer related to each other than to the bacteria.

Question 29

Which statement is true about prokaryotes? r: 0214_2014_QC_44908

A) They contain a nucleus.
B) They lack ribosomes.
C) They usually lack a cell wall.
D) They do not divide by mitosis.
E) They contain a long linear strand of DNA as the genetic material.

Question 30

Chemoautotrophs oxidize which of the following to obtain the energy necessary to reduce carbon dioxide to an organic compound?

A) hydrogen gas
B) hydrogen sulfide
C) ammonia
D) All of the choices are correct.
E) nitrites

Question 31

When conditions are unfavorable, some bacteria form

A) pili.
B) endospores.
C) galls.
D) capsules.
E) thylakoids.

Question 32

Explain the biochemical features that are unique to archaea.

Question 33

Which description best describes the cell wall of a Gram-positive bacteria?

A) It is composed of a single plasma membrane and a thin outer layer of peptidoglycan.
B) It is composed of a double layer in the plasma membrane and a thin outer layer of peptidoglycan.
C) It is composed of a double layer in the plasma membrane and a thick outer layer of peptidoglycan.
D) It is composed of a single plasma membrane and a thick outer layer of peptidoglycan.
E) It is composed of a single plasma membrane and a thin outer layer of cellulose.

Question 34

Bacterial cells pick up free pieces of DNA that were secreted by live bacteria or released from dead bacteria in their environment. This process is called

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

Question 35

Halophiles

A) require a high salt environment.
B) increase the chloride level within their cells.
C) may be chemoheterotrophs or photosynthetic.
D) all of the choices are correct.
E) use bacteriorhodopsin to capture solar energy.

Question 36

Which of the following is a mismatch?

A) thermophiles - live in extremely cold temperatures
B) methanogens - prefer anaerobic environments
C) halophiles - live in high salt environments
D) thermoacidophiles - live in high temperatures and acidic environments

Question 37

Describe how halophiles metabolize nutrients in environments that contain a high salt concentration.

Question 38

Which group of Archaea are chemoautotrophic anaerobes that will use hydrogen as an electron donor?

A) Halophiles
B) Methanogens
C) Thermoacidophiles
D) Cyanobacteria

Question 39

The endosymbiotic theory suggests that chloroplasts evolved from cyanobacteria. What features of cyanobacteria support this premise.

Question 40

Study the life cycle diagram. Label A is the ________ life cycle.

A) lysogenic
B) sexual
C) lytic
D) alternation of generations

Question 41

An environmental change, such as exposure to ultraviolet light, may cause a lysogenic virus to enter a lytic cycle. --2013

Question 42

A facultative anaerobe is an organism that can metabolize effectively in the presence or absence of oxygen.

Question 43

A Gram-negative bacteria will have a peptidoglycan layer that is sandwiched between two plasma membranes and will stain purple.

Question 44

Identify the correct sequence of events that occur during the reproduction of HIV.

A) Virus attaches to a host cell - the virus enters the cell - viral DNA is incorporated into the host DNA - reverse transcriptase occurs - viral / host DNA is turned into a viral mRNA code - the viral RNA forms into a mature virus - mature viruses leave the host cell
B) Virus attaches to a host cell - the virus enters the cell - reverse transcriptase occurs - viral DNA is incorporated into the host DNA - viral / host DNA is turned into a viral mRNA code - the viral RNA forms into a mature virus - mature viruses leave the host cell
C) Virus attaches to a host cell - the virus enters the cell - viral DNA is incorporated into the host DNA - reverse transcriptase occurs - the viral RNA forms into a mature virus - viral / host DNA is turned into a viral mRNA code - mature viruses leave the host cell
D) Virus attaches to a host cell - the virus enters the cell - viral / host DNA is turned into a viral mRNA code - viral DNA is incorporated into the host DNA - reverse transcriptase occurs - the viral RNA forms into a mature virus - mature viruses leave the host cell

Question 45

A lichen is a symbiotic relationship between cyanobacteria and fungi.

Question 46

Which enzyme enables a retrovirus to convert its' RNA genome into DNA?

A) DNA helicase
B) reverse transcriptase
C) DNA ligase
D) reverse helicase

Question 47

Study the life cycle diagram. Label B is the ________ life cycle.

A) lysogenic
B) sexual
C) lytic
D) alternation of generations

Question 48

Which of the following characteristics about saprotrophs is NOT true?

A) They are viruses that infect plant and fungal cells.
B) They are bacteria that decompose large organic molecules.
C) Saprotrophs are also called decomposers.
D) They are ecologically important in recycling matter.

Question 49

Eukarya are believed to have diverged from the bacterial line of descent. The Eukarya are, therefore, more closely related to the Bacteria than to the Archaea.

Question 50

Explain which features of cyanobacteria enable them to survive in a variety of environments.

Question 51

Pasteur's experiments are depicted in this diagram. Do the results of the first experiment confirm the prediction of Hypothesis A? Do the results of the first experiment confirm the prediction of Hypothesis B?