Chapter 20
Prokaryotes are now divided into the
archaea and bacteria
What are the two domains that the prokaryotes are classified under?
archaea and bacteria
The innermost portion of a virus' structure is made up of
either DNA or RNA
When conditions are unfavorable, some bacteria form
endospores
Study the life cycle diagram. Label B is the _____ life cycle.
lysogenic
The cycle of viral infection in which the viral DNA is integrated into the host's DNA is called the _____ cycle.
lysogenic
Study the life cycle diagram. Label A is the _____ life cycle.
lytic
Which of the following is a mismatch? A. thermophiles-live in extremely cold temps B. methanogens-prefer anaerobic environments C. halophiles-live in high salt environments D. thermoacidophiles-live in high temps and acidic environments
A
Which group of Archaea are chemoautotrophic anaerobes that will use hydrogen as an electron donor? A. halophiles B. methanogens C. thermoacidophiles D. cyanobacteria
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
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
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
D
Pasteur chose the Latin root word for "virus" meaning
poison
Bacteriophages carry portions of bacterial DNA from one cell to another in a process called
transduction
Bacterial cells pick up free pieces of DNA that were secreted by live bacteria or released form dead bacteria in their environment. This process is called
transformation
The cycle of viral infection of a bacterial cell that will cause its death most rapidly is called the ______ cycle
lytic
Ivanowsky first recognized that something smaller than a bacterium, called a filterable virus, was able to cause disease in the year
1892
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
B
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. viruse 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
B
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
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 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
Which enzyme enables a retrovirus to convert its' RNA genome into DNA? A. DNA helicase B. reverse transcriptase C. DNA ligase D. reverse helicase
B
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
B
All of the following are menas of genetic recombinations 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 choices are correct E. nitrites
D
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 bacteriorhodospin to capture solar energy
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 mn C. 10-100 um D. 1-10 um E. 50-100 nm
D
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
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
What is the correct sequence of events in the lytic cycle of a bacteriophage infection? A. Attachement, Viral DNA penetration into host cell, Integration of viral DNA into host cell DNA, Biosynthesis, Maturation, Release B. Endocytosis of virion, Uncoating, Maturation, and Release C. Attachment, Fusion of envelope and host cell membrane, Biosynthesis, Maturation, and Release D. Attachement, Viral DNA penetration, Biosynthesis, Maturation and Release
D
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 single plasma membrane and a thin outer layer of cellulose
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
Which of these is the best description of a virus? A. a noncellular living organism B. on 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 statement is true about prokaryotes? A. they contain a nucelus 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
E
Some, but not all, virus capsids are surrounded by ______
a membranous envelope
