|
| 1 |
Go |
Q:
|
Transduction is a recombinant process carried out by: |
|
A
|
viruses |
B
|
bacteria |
C
|
specialized plants |
D
|
plasmids |
|
|
|
Tags:
Viruses | |
|
| 2 |
Go |
Q:
|
HIV is an RNA virus, implying that it |
|
A
|
Destroys the infected cells' RNA |
B
|
Prevents the efficient travel of mRNA through the infected cell |
C
|
Replicates through RNA transcription in the infected cell |
D
|
The virus' genome is composed of RNA |
|
|
|
Tags:
Viruses | |
|
| 3 |
Go |
Q:
|
Many adenoviruses require access to host cell DNA
yet lack the transport mechanisms to get their
viral nucelic acids and enzymes into the nucleus.
Which of the following would be expected
observations of adenoviral infectivity and
replication? |
|
A
|
the inability to infect dividing cells |
B
|
the inability to infect cells in G0 |
C
|
the inability to infect epithelial cells |
D
|
the inability to infect eukaryotic cells |
|
|
|
Tags:
Mitosis and Meiosis | Viruses | |
|
| 4 |
Go |
Q:
|
Certain viruses lack 5' caps on their mRNA sequences. Which of the following answers explains one of the ways in which such viruses produce their proteins?
|
|
A
|
They carry their own ribosomes which do not need 5' caps in order to initiate translation
|
B
|
They use Internal Ribosomal Entry Sites (IRES) which allow for the assembly of cellular ribosomes to initiate translation
|
C
|
They carry out protein synthesis prior to infection; the mRNA is incorporated into the host nucleic acids in dormancy
|
D
|
They initiate translation from the 3' polyA tail instead of the 5' cap to avoid the problem.
|
|
|
|
Tags:
Genetic Code, Transcription, Translation | Viruses | |
|
| 5 |
Go |
Q:
|
The lytic viral life cycle involves the lysis of the host cell and the release of virus particles. In contrast, the lysogenic cycle involves the dormancy of a virus within its host. Given the persistent DNAse and RNAse degradation in the cell, which of the following viruses is most likely to be involved in a lysogenic cycle? |
|
A
|
a virus which is engaging the host cell in replication of more viral genome than the host is capable of degrading |
B
|
a virus which has sent its genome to the nucleus as a separate body from the genome, where it is safe from degradation by the host defenses |
C
|
a virus which has encapsulated itself within a protective protein coat |
D
|
a virus which has integrated its genome into the host genome |
|
|
|
Tags:
Viruses | |
|
| 6 |
Go |
Q:
|
Both Group VI and VII viruses are retroviruses. Group VI is characterized by ssRNA as the genome, while Group VII is characterized by dsDNA as the genome. As retroviruses, both Groups code for reverse transcriptase. The reverse transcriptase in both Groups used for which of the following purposes? |
|
A
|
transcription of genomic RNA from mRNA |
B
|
transcription of DNA from RNA |
C
|
transcription of mRNA from genomic RNA |
D
|
transcription of mRNA from DNA |
|
|
|
Tags:
Genetic Code, Transcription, Translation | Viruses | |
|
| 7 |
Go |
Q:
|
A virus injects its DNA into a host animal cell. Which of the following is a necessary step for propagation of the viral DNA in the cell progeny and future generations of that cell? |
|
A
|
Initiation of a promoter |
B
|
Inactivation of equivalent host genes |
C
|
Entry into the nucleus |
D
|
Integration of the DNA into at host chromosome |
|
|
|
Tags:
Control of Gene Expression in Eukaryotes | Viruses | |
|
| 8 |
Go |
Q:
|
Which of the following is necessarily true for all viruses? |
|
A
|
Contains a protein coat which stores genetic information |
B
|
Genetic material from the virus enters the genome of the host |
C
|
Contains the enzyme reverse transcriptase |
D
|
Must be able to bind to at least some bacterial surface proteins |
|
|
|
Tags:
Viruses | |
|
| 9 |
Go |
Q:
|
Which of the following contents of HIV is most vital for the ability of HIV to insert its genomic data into the genome of the host? |
|
A
|
A spherical capsid |
B
|
Single stranded DNA, rather than double stranded |
C
|
Both DNA and RNA |
D
|
Reverse transcriptase |
|
|
|
Tags:
Viruses | |
|
| 10 |
Go |
Q:
|
Which of the following is the approximate size-range for viruses?
|
|
A
|
20-500 picometers
|
B
|
20-500 Angstroms
|
C
|
20-500 nanometers
|
D
|
20 - 500 mirometers
|
|
|
|
Tags:
Viruses | |
|
| 11 |
Go |
Q:
|
Which of the following best describes viruses?
|
|
A
|
Obligate extracellular parasites
|
B
|
Obligate intracellular parasites
|
C
|
Facultative extracellular parasites
|
D
|
Facultative intracellular parasites
|
|
|
|
Tags:
Viruses | |
|
| 12 |
Go |
Q:
|
A DNA virus is noted to infect muscle cells. The virus inserts its DNA into the cells, which is then integrated into the chromosome. Which of the following is true about the virus? |
|
A
|
It follows a lytic life cycle. |
B
|
It follows a lysogenic life cycle. |
C
|
The virus affects calcium ion levels in the muscle cell. |
D
|
It must contain reverse transcriptase. |
|
|
|
Tags:
Viruses | |
|
| 13 |
Go |
Q:
|
Horizontal gene transfer occurs when one organism receives genetic material from another organism without being a descendant of the organism. Which of the following describes horizontal gene transfer? |
|
A
|
Cell A is produced by mitosis from Cell B which is produced by mitosis from Cell C. Cell A has genes from Cell C. |
B
|
Cell A is produced by mitosis from Cell B. Cell A has genes from Cell B. |
C
|
Cell A and Cell Z are in different kingdoms. Cell Z inserts genes into Cell A. |
D
|
Cell A and Cell Z are in different kingdoms. The two cells share a gene through ancestral decent. |
|
|
|
Tags:
Prokaryotes | Viruses | |
|
| 14 |
Go |
Q:
|
Which of the following does not occur during viral infection of a host cell? |
|
A
|
attachment and penetration into the host cell |
B
|
uncoating of the viral genome |
C
|
multiplication of viral particles via binary fission |
D
|
cytopathic effects on the host cell |
|
|
|
Tags:
Viruses | |
|
| 15 |
Go |
Q:
|
Cytomegalovirus is a type of herpes virus which easily infects people. The majority of people infected are unaware of the infection, and the virus integrates into the host genome and almost always lies dormant for the lifespan of the any infected patient. This information suggests which of the following regarding the population effects of cytomegalovirus? |
|
A
|
Immunocompromised patients will be unable to clear the viral infection while healthy people will be able to remove the virus from their bodies. |
B
|
The virus cannot spread by person-to-person contact and must be contracted directly from the viral reservoir. |
C
|
Infection with the virus creates and immune response that is capable of clearing other herpes viruses like herpes simplex 1 and 2. |
D
|
The percentage of people infected with cytomegalovirus should be greater for the elderly than for children. |
|
|
|
Tags:
Viruses | Immune System | |
|
| 16 |
Go |
Q:
|
A specific RNA virus follows a lysogenic life cycle. Which of the following is necessary for the survival of the virus in this particular life cycle? |
|
A
|
A protein capsid bound within a lipid membrane |
B
|
Restriction endonucleases |
C
|
RNA polymerase |
D
|
Reverse transcriptase |
|
|
|
Tags:
Viruses | |
|
| 17 |
Go |
Q:
|
A biologist has isolated the mRNA used for the translation of a particular protein. He wants to transform the gene for the protein into another organism, for which he needs DNA strands. Which of the following enzymes is most adequately suited to this task? |
|
A
|
reverse transcriptase |
B
|
DNA polymerase |
C
|
topoisomerase |
D
|
transcriptomerase |
|
|
|
Tags:
Genetic Code, Transcription, Translation | Recombinant DNA and Biotechnology | Viruses | |
|
| 18 |
Go |
Q:
|
Which process involves transfer of DNA from a virus to a bacterium? |
|
A
|
Transcytosis |
B
|
Translation |
C
|
Transposition |
D
|
Transduction |
|
|
|
Tags:
Prokaryotes | Viruses | |
|
| 19 |
Go |
Q:
|
RNA-dependent RNA polymerase catalyzes the replication of RNA from an RNA template as opposed to the typical DNA-dependent RNA polymerase present during gene transcription. Many human RNA viruses require RNA-dependent RNA polymerases to replicate their genomes. This polymerase must be encoded by the virus itself; it cannot be sourced from the host. The reason for this is that |
|
A
|
human RNA-dependent RNA polymerase is incompatible with viral RNA |
B
|
human RNA-dependent RNA polymerase will recognize viral RNA as foreign and trigger an immune response. |
C
|
human RNA-dependent RNA polymerases will degrade rather than replicate viral RNA. |
D
|
humans lack RNA-dependent RNA polymerases. |
|
|
|
Tags:
Genetic Code, Transcription, Translation | Viruses | |
|
| 20 |
Go |
Q:
|
A test tube filled with virions (virus particles) is enzymatically digested into component parts in order to isolate the various biological molecules in the sample. Which of the following would least likely be seen? |
|
A
|
The presence of capsid proteins |
B
|
The presence of uracil and thymine |
C
|
The presence of double stranded RNA |
D
|
The presence of viral enzymes |
|
|
|
Tags:
Viruses | |
|
| 21 |
Go |
Q:
|
A newly emerged virus is found to infect human glomerular cells. Infected cells from an infected kidney are examined in a laboratory. The cells are spun down and the cytosolic fraction of the cells are measured for viral content. There are no traceable viral proteins nor genomic information found in this fraction. Which of the following can hold true about this virus? |
|
A
|
The virus underwent autolysis and vanished from the cell |
B
|
The virus has integrated with the host genome |
C
|
The virus was destroyed through the release of antibiotic from the innate immune system |
D
|
The virus is undergoing the lytic cycle |
|
|
|
Tags:
Viruses | |
|
| 22 |
Go |
Q:
|
Which of the following components would not be found in an RNA virus? |
|
A
|
Reverse transcriptase |
B
|
Capsid |
C
|
Double-stranded RNA |
D
|
DNA-dependent RNA polymerase |
|
|
|
Tags:
Viruses | |
|
| 23 |
Go |
Q:
|
Zoonotic viruses are able to infect multiple different species. Viral entry points are often highly specific; if a cell lacks the specific protein or marker that a virus uses to enter, the cell will not be infected. Which of the following can be expected from the entry proteins on cells that can be infected by a zoonotic virus? |
|
A
|
Homology and degree of amino acid sequence identity for the protein have little impact on whether other species are susceptible to the virus. |
B
|
Members of a class of species are more likely to be infected by the zoonotic virus than members of a family of species |
C
|
Other species have a homologous protein with a high degree of identity with the cells in question. |
D
|
No other species share a similar protein in terms of amino acid sequence. |
|
|
|
Tags:
Viruses | |
|
| 24 |
Go |
Q:
|
Rheumatoid factor (RF) is an autoantibody in the body commonly seen in patients with rheumatoid arthritis. Autoantibody implies that it is an antibody which binds to the individual's own proteins. Which of the following would not be a molecule RF could bind to?
I. antibodies
II. membrane phospholipids
III. viral reverse transcriptase |
|
A
|
I and II only |
B
|
II only |
C
|
II and III only |
D
|
I, II, and III |
|
|
|
Tags:
Eukaryotic Cells | Viruses | |
|
| 25 |
Go |
Q:
|
Despite being very different viruses, rhinovirus and influenza virus (both affecting the respiratory system) can cause some similar symptoms. The reason for this is: |
|
A
|
both viruses have similar replication mechanisms. |
B
|
all viruses induce the same responses by the body. |
C
|
many immune responses are generic and similar regardless of the pathogen. |
D
|
the symptoms are caused by the medication used to treat the viruses. |
|
|
|
Tags:
Viruses | Immune System | |
|
| 26 |
Go |
Q:
|
Efavirenz is a non-competitive inhibitor of reverse transcriptase (RT) found in HIV. It is included in the treatment regimen for HIV patients. Which of the following likely does not hold true for Efavirenz? |
|
A
|
Efavirenz binds to a site outside of the the active site of RT |
B
|
Efavirenz cannot be outcompeted with RT substrate |
C
|
Increased production of RT by HIV could overcome Efavirenz therapy |
D
|
Efavirenz has a structure similar to host nucleotides |
|
|
|
Tags:
Enzyme Structure and Function | Viruses | |
|
| 27 |
Go |
Q:
|
Gonorrhea is a sexually transmitted infection caused by the bacteria N. gonorrhoeae. N. gonorrhoeae is characterized by pili and other surface proteins which are used to adhere to genitourinary tissues in humans. These genes that code for pili undergo continuous antigenic variation through homologous recombination and phase variation (turning the genes "on" and "off"). Although growing antibiotic resistance has been an issue, vaccinations are not considered a very plausible preventative measure for gonorrhea. Why?
|
|
A
|
Antibiotic treatment has been very effective and new antibiotics are constantly created. |
B
|
There are no surface antigens on N. gonorrhoeae for which antibodies can be generated against. |
C
|
A bacterial infection by N. gonorrhoeae elicits a rapid natural immune response, so a vaccine is not required. |
D
|
The antigenic variation of the N. gonorrhoeae pili genes generates constant new variations of the pili surface antigens. |
|
|
|
Tags:
Viruses | Immune System | |
|
| 28 |
Go |
Q:
|
Certain viruses infect their hosts not by injecting nucleic acid into the cell, but by activating receptors to bring the whole virus particle into the cell. This import mechanism is an example of which of the following? |
|
A
|
Receptor-mediated endocytosis |
B
|
Pinocytosis |
C
|
Exocytosis |
D
|
Facilitated diffusion |
|
|
|
Tags:
Eukaryotic Cells | Viruses | |
|
| 29 |
Go |
Q:
|
Which of the following must be true of a virus which uses the lysogenic cycle to replicate? |
|
A
|
The virus is a DNA virus. |
B
|
The virus integrates into the host cell genome. |
C
|
The virus is taken into the cell by receptor-mediated endocytosis. |
D
|
The viral DNA in lysogeny cannot be transmitted through vertical gene transfer of the host. |
|
|
|
Tags:
Viruses | |
|
| 30 |
Go |
Q:
|
Virus particles placed in a nutrient broth will not replicate unless which of the following is present? |
|
A
|
phospholipids for membrane synthesis |
B
|
reverse transcriptase |
C
|
living host cells |
D
|
plasmids |
|
|
|
Tags:
Viruses | |
|
| 31 |
Go |
Q:
|
A researcher wants to insert a series of genes too large to be practically transferred by a plasmid. The researcher places them into a viral capsid and infects a bacterium with the virus. This method of gene transfer is known as: |
|
A
|
transformation |
B
|
transduction |
C
|
conjugation |
D
|
vertical gene transfer |
|
|
|
Tags:
Prokaryotes | Viruses | |
|
| 32 |
Go |
Q:
|
Viral genomes can often be used as a template for translation of viral proteins. These genomes are most similar to which of the following? |
|
A
|
template strand DNA |
B
|
coding strand DNA |
C
|
mRNA |
D
|
tRNA |
|
|
|
Tags:
Viruses | |
|
| 33 |
Go |
Q:
|
Where sanitation is a challenge, measles patients are often given antibiotics for skin infection. The purpose of the antibiotics is to: |
|
A
|
prevent the measles virus from spreading on the skin and becoming more infectious to others. |
B
|
limit viral replication and reduce the amount of time the patient is sick. |
C
|
prophylactically prevent skin rashes and wounds from becoming infected with opportunistic bacteria. |
D
|
reduce the pain and itch associated with the viral infection. |
|
|
|
Tags:
Prokaryotes | Viruses | |
|
| 34 |
Go |
Q:
|
Virus can be ruled out as the causative agent of a disease if the pathogen lacks which of the following? |
|
A
|
nucleic acid |
B
|
phospholipid bilayer |
C
|
glycosylated protein |
D
|
membrane-bound organelles |
|
|
|
Tags:
Viruses | |
|
| 35 |
Go |
Q:
|
Viral serotypes are classified by differing surface antigens. Rhinovirus has over 100 known serotypes. In order for a vaccine to be effective against most rhinovirus infections, which of the following should be true? |
|
A
|
High conservation of all surface antigens between the different serotypes. |
B
|
High conservation of at least one important surface antigen between the different serotypes. |
C
|
No conservation of at least one important surface antigen between the different serotypes. |
D
|
No conservation of any surface antigens between the serotypes. |
|
|
|
Tags:
Viruses | |
|
| 36 |
Go |
Q:
|
Rinderpest is a virus related to measles that infects cattle through a respiratory route of infection. However, the virus particles are quite fragile and can easily be inactivated when exposed to heat, sunlight, or desiccation. Which of the following cattle populations would be most susceptible to a mass outbreak of rinderpest? |
|
A
|
Cattle which spend all of their time grazing outdoors in a desert environment. |
B
|
Cattle which spend most of their time in closed-quarters. |
C
|
Cattle that do not have regular access to a single watering hole. |
D
|
Cattle that are fed a diet of grains rather than grasses. |
|
|
|
Tags:
Viruses | |
|
| 37 |
Go |
Q:
|
A researcher is working to create a targeted therapy for a specific retrovirus. Which of the following provides a reason that using a nonselective RNA splicing enzyme as a medication may not work as an effective drug? |
|
A
|
RNA splicing is an important component for retrovirus action, and thus would activate the virus further |
B
|
retroviruses do not contain RNA |
C
|
retroviruses would likely evolve and become immune to such therapy |
D
|
the enzyme would also splice host RNA |
|
|
|
Tags:
Viruses | |
|
| 38 |
Go |
Q:
|
Which of the following is not a plausible way that a virus could evolve to gain resistance to an antiviral agent? |
|
A
|
Encode a different protease enzyme |
B
|
Contain a capsid which contains different cell surface receptor proteins |
C
|
Encode a different integrase enzyme |
D
|
Encode virion progeny which do not contain a capsid |
|
|
|
Tags:
Viruses | |
|
| 39 |
Go |
Q:
|
Which of the following provides a mechanism for prion reproduction? |
|
A
|
modifying transcription at a genetic level to cause further production of prion molecules |
B
|
prion degradation creates additional prion molecules |
C
|
prion attaches to ribosomal molecules to cause production of prion molecules rather than baseline proteins |
D
|
induction of normal proteins into a prion configuration |
|
|
|
Tags:
Viruses | |
|
| 40 |
Go |
Q:
|
Which of the following is necessary for a viral genome? |
|
A
|
Either a DNA or RNA genome and either single or double stranded |
B
|
A double stranded DNA-based genome or a single stranded RNA genome |
C
|
A genome which is composed of double-stranded DNA or RNA |
D
|
A circular genome (i.e., there is no formal beginning or end to the genome) |
|
|
|
Tags:
Viruses | |
|
| 41 |
Go |
Q:
|
A virus is discovered which causes indirect destruction to nuclear envelopes within cells. This property would be expected to have little effect on |
|
A
|
neural cells |
B
|
phagocytes |
C
|
pancreatic duct cells |
D
|
red blood cells |
|
|
|
Tags:
Viruses | Circulatory System | |
|
| 42 |
Go |
Q:
|
An experiment calls for the sequencing of a 1kb fragment of viral genetic material. The nucleotide base composition is found to be the following: 250 adenine, 248 thymine, 300 guanine, and 202 cytosine. Which of the following choices BEST supports the data? |
|
A
|
The virus contains single-stranded DNA
|
B
|
The virus contains double-stranded DNA
|
C
|
The virus contains single-stranded RNA
|
D
|
The virus contains double-stranded RNA
|
|
|
|
Tags:
Viruses | |
|
| 43 |
Go |
Q:
|
Viruses can exploit the gap junctions found in certain types of tissue, mainly because of their close packing. Which of the following tissue types is most prone to this scenario? |
|
A
|
Nervous tissue |
B
|
Epithelial tissue |
C
|
Cardiac tissue |
D
|
Muscle tissue |
|
|
|
Tags:
Viruses | Eukaryotic Tissues | |
|
| 44 |
Go |
Q:
|
Which of the following would NOT enhance phagocytosis by macrophages? |
|
A
|
Clumping of microbes
|
B
|
Decreased phagocyte surface receptors |
C
|
The binding of antibodies to the surface of microbes
|
D
|
Increased concentration of peroxides inside lysosomes
|
|
|
|
Tags:
Immune System | Viruses | |
|
| 45 |
Go |
Q:
|
A virus which uses the lysogenic cycle: |
|
A
|
is capable of integrating within a prokaryotic genome. |
B
|
must necessarily lyse the host cell. |
C
|
is incapable of infecting prokaryotic cells. |
D
|
has a non-DNA based genome. |
|
|
|
Tags:
Viruses | |
|
| 46 |
Go |
Q:
|
Which of the following structures would be unexpected to find in a virus?
I. phospholipids
II. ribosomes
III. double stranded DNA
IV. protein coating
|
|
A
|
I and II only |
B
|
II only |
C
|
II and III only |
D
|
III and IV only |
|
|
|
Tags:
Viruses | |
|
| 47 |
Go |
Q:
|
An experimenter wishes to display transduction as it relates to bacteria. Which of the following is required in transduction?
I. physical contact between two bacterial cells
II. a virus
III. binding of virus to a bacterium |
|
A
|
I only |
B
|
II only |
C
|
II and III only |
D
|
none of the above are correct |
|
|
|
Tags:
Viruses | |
|
| 48 |
Go |
Q:
|
The protein shell of a virus: |
|
A
|
may be coated in a lipid membrane. |
B
|
typically only has a spherical structure. |
C
|
may only contain single or double stranded RNA. |
D
|
is referred to as the viral envelope. |
|
|
|
Tags:
Viruses | |
|
| 49 |
Go |
Q:
|
Retroviruses contain an enzyme called reverse transcriptase which is important to: |
|
A
|
allow for viral passage into the cell through the membrane. |
B
|
integrate the host genome into the viral genome. |
C
|
expulsion of virus particles out of the cell. |
D
|
form DNA from RNA of the virus. |
|
|
|
Tags:
Viruses | |
|
|
We can teach you how to crush the MCAT!
Learn More
|
