Chapter 20: Viruses, Bacteria, and Archaea

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.

A. archaea and bacteria.

When conditions are unfavorable, some Gram positive bacteria form A. pili. B. endospores. C. galls D. capsules. E. thylakoids.

B

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. A and B only.

D

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

D

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 above choices are correct. E. B and C only are correct.

E

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

A

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. True False

False

An environmental change, such as exposure to ultraviolet light, may cause a lysogenic bacterium to enter a lytic cycle. True False

True

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

True

A lichen is a symbiotic relationship between cyanobacteria and fungi. True False

True

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

A

Study the life cycle diagram. Label B is the ________ life cycle. A. lysogenic B. sexual C. lytic D. alternation of generations

A

The cycle of viral infection in which the viral DNA is integrated into the bacterial DNA is called the _______ cycle. A. lysogenic B. lysozyme C. lytic D. lysol E. lysosome

A

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

E

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.

A.

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.

B

If a virus is latent, it A. cannot be a retrovirus. B. has not entered a lytic cycle. C. has not entered a lysogenic cycle. D. is gaining a new envelope via "budding." E. is easy to develop immunity against it.

B

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.

B

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.

B

This bioterrorist agent was sent through the mail and inhaled to produce illness and death in five people. It produces endospores and is called A. Clostridium tetani. B. Bacillus anthracis. C. Vibrio cholera. D. Staphylococcus aureus.

B

Which of the following is not a viral disease? A. AIDS B. tetanus C. Ebola Hemorrhagic fever D. West Nile Encephalitis

B

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.

C

Pasteur chose the Latin root word for "virus" meaning A. extremely small. B. non-living. C. poison. D. contagious. E. particle.

C

Study the life cycle diagram. Label A is the ________ life cycle. A. lysogenic B. sexual C. lytic D. alternation of generations

C

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

C

Which of these diseases could NOT be treated with antibiotics? A. chlamydia B. plague C. influenza D. scarlet fever

C

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.

C

All of the following are means of genetic recombination in prokaryotes EXCEPT A. conjugation. B. transformation. C. transduction. D. crossing over.

D

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 above choices are correct. E. A and C only.

D

Halophiles A. require a high salt environment. B. have a chloride pump that pumps chloride into the cell. C. may be chemoheterotrophs or photosynthetic. D. All of the above choices are correct. E. A and C only are correct.

D

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.

D

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

D

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.

D

Which of the following characterize prions? A. Prions are proteinaceous infectious particles. B. Prions cause TSEs, transmissible spongiform encephalopathies. C. Prions are misshapen proteins that may interact with a normal prion protein to change its shape. D. All of the choices are correct. E. A and B only.

D

Which of the following could be used to grow viruses in the laboratory? A. chicken eggs B. cell culture C. bacteria D. All of the choices could be used.

D

Which statement is true about prokaryotes? 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 single circular DNA molecule as the genetic material.

D

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.

E. they are harmful human pathogens.

A circular piece of RNA that interrupts the normal regulatory systems in plants, thereby causing disease is a A. viroid. B. prion. C. plant virus. D. bacterium.

A

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.

A

A prophage is a form of virus that attacks only plants cells. True False

False