Med Micro Exam 3 – Flashcards
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Unlock answersHow are enveloped viruses released from cells? a) rupture of host cell b) lysis c) phage lysozyme breaks the cell wall d) budding e) uncoating |
| d) budding |
Which of the folowing statements about oncogenes is FALSE? a) genetic material of oncogenic viruses becomes integrated into host-cell DNA b) only DNA viruses can be oncogenic c) Activated oncogenes transform normal cells into cancerous cells d) transformed cells have an increased growth rate and loss of contact inibition. |
| b) Only DNA viruses can be oncogenic |
Which of the following are MISMATCHED? a) RNA->DNA->RNA=RNA retrovirus b) RNA->RNA->RNA=RNA non-retrovirus c) DNA->DNA->DNA=DNA containign virus d) DNA->RNA-> DNA= HBV virus e) All of these are correct |
| e) All of these are correct |
The poliovirus has each of the following properties, except: a) single stranded genome b) enveloped c) icosahedral symmetry d)RNA genome
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| b) enveloped |
Folllowing entry of the genome of the poliovirus into the cell, the next step in the replicative cycle of the virus is: a) transcription of the genome b)replication of the genome to form complementary RNA c)synthesis of DNA using the genome as a template d)translation of the genome. |
| d)translation of the genome |
Which statement concerning the replicative cycle of the poliovirus is FALSE? a) The genome of the virus replicates in the nucleus of the cell b)During this cycle, a polyprotein is synthesized c) Polioviruses are lytic, in that they burst out of the cell during their release d) translation is coupled to transcription |
| a) the genome of the virus replicates in the nucleus of the cell |
Which statement is FALSE? a) the OPV elicits the formation of intestinal IgA antibodies, the IPB does not b) Presently, the USA uses the OPV routinely to vaccinate people in the USA c) The mOPV vaccine gives protection only against poliovirus serotype 1 d) the IPV gives protection against three serological types of the poliovirus |
| b) Presently, the USA uses the OPV routinely to vaccinate people int he USA |
Post polio syndrome occurs because: a)antibodies to the poliovirus hve been depleted b) the rate of degeneration of old neuron sprouts exceeds the rate of the regeneration of new sprouts c) the victims of this disease received the IPV instead of the OPV d) the victims of this disease were infected with serotype 1 of the virus |
| b) the rate of degeneration of old neuron sprouts exceeds the rate of the regeneration of new sprouts |
Which statesment is FALSE? a) It is thought that the disease polio is a 'disease of civilization' in that it has been a disease of humans for thoughs of years. b) a major break through in poliovirus reasearch occured when it was learned that the virus can be replicated in monkey kidney cells. c) During an outbreak of polio, about 1% of the people infected were paralyzed d) In humans the virus replicates in epithelial cells that lined the digestive tract in some nerve cells e) None of theses are FALSE |
| e) None of these are FALSE |
Which statement is FALSE? a) the Herpese viruses are not evolving as fast as the Picornaviruses b) RNA dependent RNA polymerase does not have repair enzymes associated with it. c) The mutation rate of the influenza virus genome is faster than that of the EBV d) DNA dependent DNA polymerase is "noisy" and leads to a high rate of mutation. |
| d) DNA dependent DNA polymerase is "lnoisy and leads to a high rate of mutation |
Which is mismatched?
a) HSV2-chickenpox b) HSV1-cold sores/ fever blisters c) HHV8-Kaposi's sarcoma d) EBV-mononucleosis |
a) HSV2-chickenpox ; HSV2 is for general herpes |
Which statement concerning the EBV is FALSE? a)research has shown that EBV entered the human race relatively recently b) the permissive cell of this virus is the epithelial cell of the oropharynx c) this virus transforms certain lymphocytes, and hence, can be considered to be a tumorigenic virus d) the EBV is associated with many malignancies like Burkitt's lymphoma and Hodgkin's disease |
| a) research has shown that EBV entered the human race relatively recently |
Which does NOT happen during the clipse phase of hte replicative cycle of the EBV? a) Transcription of genes ocurs in the sequential manner b) the DNA of the virus replicates by a DNA dependent DNA polymerase brought into the cell with the virus c) Late translation results in the structural proteins of the virus d) The genome is replicated in the cytoplasm. |
| d) the genome is replicated in the cytoplasm |
Which statement concerning the lat I, II, and III cells is FALSE? a) the lat III cells replicate, but the lat I and II cells do not. b) the late III cels express more viral genes than do the lat I cells c) the lat II cells are tumor cells or transformed cells d) T cytotoxic cells kill lat III cells |
| c) the lat II cells are tumor cells or transformed cells |
Which of the following are part of the Beta-family of Herpes virus? ; a) EBV1, EBV2 b) HSV-1, HSV-2 c) HHV8 d) CMV, HHV6, HHV7 |
a) EBV1, EBV2 (gamma) b) HSV-1, HSV-2 (alpha) c) HHV8 (gamma) d) CMV, HHV6, HHV7 (beta) |
The herpes viruses are: a) DS DNA viruses, that have icosahedral symmetry and an envelope b) DS DNA viruses, that have helical symmetry and an envelope c) SS plus stranded RNA viruses that have icosahedral symetry, and no envelope d) SS plus RNA virus, which have helical symmetry and an envelope. |
| a) DS DNA viruses, that have icosahedral symmetry and an envelope |
Which statement regarding HAV is FALSE? a) the HAV is in the family Picornaviridae b) This is an enveloped virus that buds out of hepatocytes c) the HAV may be acquired by eating shellfish from water contaminated with this virus d) the genome of this virus is RNA |
a) the HAV is in the family Picornaviridae b) This is an enveloped virus that buds out of hepatocytes (non-enveloped, lysis) c) the HAV may be acquired by eating shellfish from water contaminated with this virus d) the genome of this virus is RNA |
Which statement is FALSE? a) We do not have a vaccine for the HEV b) We do have a vaccine for the HAV c) We have a vaccine for the HCV d) A vaccine for HBV gives protection against infection with HDV ; |
| c) We have a vaccine for the HCV |
Which statement concerning the HDV is FALSE? a) This is not really a virus b) The HDV consists of a covalently closed, single stranded circle of RNA surrounded by an envelope that contains the delta antigen c) the HDV worsens the affects of infection with the HBV d) HCV needs HDV to replicate inside a hepatocyte |
| d) HCV needs HDV to replicate inside a hepatocyte |
Which statement concerning the replicaiton of the HBV is FALSE?; a) the direct repeats ont eh genome play a role int he replicaiton of the genome b) during transcription of the gneome, gnees are read on more than one reading frame c) replicaiton takes place only in the nucleus, with budding from nuclear envelope d) convalently-closed ciruclar DNA is formed in the nucleus from the genome. |
| c) replicaiton takes place only in the nucleus, with budding from nuclear envelope |
Which statement is FALSE? a) Protooncogenes are normal cellular genes b) some viruses have protooncogenes c) a transformed cell is the laborator equivalent of a tumor cell in an animal d) a mutated tumor suppressor gene may promote tumor formation |
| b) some viruses have protooncogenes |
The HBV virus has each of the following properties, except: a) has the smallest genome of any known virus b) is carried by over 350 million people in the world c) infection with this virus may lead to hepatocellular carcinoma d) is transmitted via the fecal-oral route |
| d) is transmitted via the fecal-oral route |
Which statement is FALSE? a) In the USA, infection with HBV becomes chronic in about 1% of people infected with the virus b) the HBV is very unusual in that it is a DNA containing virus that replicates through an RNA intermediate c) THERE is evidence to suggest that the X gene product of HBV acts as a viral oncogene d) Many o fhte symptoms of the disease hepatitis are due to the immune system reacting to virus infected cells. |
| a) In the USA, infection with HBV becomes chronic in about 1% of people infected with the virus |
Which is mismatched? a) HAV-acute hepatitis b) HEV-spread via the fecal-oral route c) HGV-spread by the fecal-oral route d) HCV- chronic hepatitis |
| c) HGV-spread by the fecal-oral route |
Epidemiological studies of the measles virus has shown each of the followin except: a) the disease dies out sooner or a smaller island that is densely populated than it does on a larger island with fewer in habitants per square mile b) the fewer births each year on an island, the sooner the spread of the disease stops c) herd immunity does not afect the spread of the measles virus on an island d) population size and density greatly affects the spread of the measles virus through a community. |
| c) herd immunity does not affect the spread of the measle virus on an island |
Following adsorption and penetration of the measles virus into a cell, the first step in the eclipse phase of replicaiton is: a)translation of the genome b) synthesis of mRNA c) synthesis of complementary - RNA d) genome synthesis |
| b) synthesis of mRNA |
Which statement concerning primary transcription of the measles virus genome is FALSE? a) This occurs via the activity of three proteins, the P, N, and L proteins b) during primary transcription, the enzyme complex stutters when it reaches a polyU region, andfalls off the template. c) Full length +RNA is synthesized. d) not all of the intergenic sequences of the genome are transcribed. |
| c) Full length +RNA is synthesized. |
Which statement concerning the measles if FALSE? a) measles will be with us for a long time since the disease is not preventable b) a vitamin A deficiency promotes complications of a measles virus infection c) This virus is spread via the respiratory tract and is considered to be VERY infectious. d) The virus suppresses certain parts of the immune system. |
| a) measles will be with us for a long time since the disease is not preventable |
The worldwide initiative to eradicate the disease measles from the world may potentially succeed for each of the following reasons, except: a) the available vaccine is relatively inexpensive b) successful vaccination give lifelong immunity to the virus. c) the vaccine is 100% effective d) humans are hte only host of the virus. |
| c) the vaccine is 100% effective |
The measles virus has each of the following properties except: a) segmented genome b) -SS RNA c) helical capsid d) enveloped |
| a) segmented genome |
Which of the following are MISMATCHED? a) Polio=picornaviridiae b) Measles= Rubella c) Hepatitis A=picornaviridiae d) Varicella Zoster=Herpesviridiae |
| b) Measles= Rubella (German) |
The influenza A virus has each of the following properties, except: a) eight segments of SS RNA, each in its own helical capsid. b) hemagglutinin and neuraminidase peplomers c) segments with terminally , inverted complementary base sequences d) segments with 5' caps and 3' poly A tails. |
| d) segments with 5' caps and 3' poly A tails. |
Which of the following is FALSE? a) Human lungs mainly have alpha 2,3 sialic acid linkages on their receptors b) Human-tropic Influenza HA peplomeres bind to cell receptors with alpha 2,6 linkages. c) Avian-tropic Influenza Ha peplomers bind to cell receptors with alpha 2,3 linkages. d) when avia-tropic virus is inhaled deeply into the alveolus of the human lung, it may encounter some alpha 2,3 sialic acid type receptors. |
| a) Human lungs mainly have alpha 2,3 sialic acid linkages on their receptors |
Which statement is FALSE? a) Tyep B influenza viruses infect only humans b) Typically only influenza viruses with hemagglutinin peplomers type 1, 2, and 3 infect humans c) Translation of the virus mRNA occurs in the nucleus of the host cell. d) the genome of the influenza A virus encodes 10 proteins |
c) translaiton of the virus mRNA occurs in the nucleus of the host cell. ; should be in the cytoplasm, not nucleus |
Which statement concerning the Spanish flue of 1918 is FALSE? a) the symptoms of this flu were different from the typical respiratory symptoms humans have when infected with the influenza virus. b) this flu killed an extraordinarily high number of children up to the age of 3 or 5 years. c) the virus that caused this pandemic was an avian virus originally d) this flue came in three waves of infection in humans during the years 1918 and 1919. |
| b) this flu killed an extraordinarily high number of children up to the age of 3 or 5 years. |
The genome of this influenza virus does each of the following except: a) serves as a tempalte for the synthesis of mRNA b) serves as either one gene or two genes, depending on the segment c) serves as mRNA that is translated d) serves as a template for the synthesis for A(-)cRNA |
| c) serves as mRNA that is translated |
Which statement concerning antigenic shift is FALSE? a) This is due to a point mutation in the genome of the virus b) this may occur in swine infectedwith an avian virus and a human virus. c) a serologically new type of virus results from antigenic shift. d) this occurs due to genetic reassortment of viral segments in ta host cell. |
| a) This is due to a point mutation in the genome of the virus |
Studies indicate that the H5N1 influenza virus has been transmitted in each of th efollowing ways ,except: a) domestic fowl to domestic fowl b) domestic fowl to cat c) migratory birds to domestic birds d) domestic birds to humans e) humans to humans |
| e) humans to humans |
Ways to control the spread of the H5N1 virus include each of the following, except: a) vaccinating all poultry b) killing infected domestic birds c) killing wild birds d) giving antiviral drugs to poultry |
| c) killing wild birds |
| Name the 5 steps of a viral life cycle |
1. Attachment 2. Penetration 3. Biosynthesis 4. Maturation 5. Release |
| Oncogenes are generally considered detrimenta; however, we discussed one useful thing aobut oncogenes. Why or how can oncogenes be useful to scientists? |
| They can be used to study transformed (carcinogenic) cells. |
| Discuss the similarities and differences between HBV and HIV |
Both uses reverse transcriptase. HIV turn its RNA into DNA and then the RNA. HBV is a DNa virus that forms its DNA to RNA to DNA. HIV is a retrovirus and HBV is an unusual DNA virus in that it behaves like the opposite of a retrovirus.; ; ??? add on |
Are viruses alive? Describe the ways in which viruses are or are not alive? ; 2 alive reasons 2 not alive reasons |
Alive reason- they have genetic material that is replicated and passed down. - can perform biological actions (ex. transcription, translation) - uses energy -made up of cells ; ; Not alive- needs to be in a ost cell to perform any biological action, no metabolism outside the host. - Has no biological functionality of its own outside of the host -doesn't use or have ribosomes -can be reconstructed in the lab? -made up of chemicals
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| Why is it that in some cases, infection of B cells with the EBV results in mononucleosis, while in other cases, it sresult sin Burkitt's lympoma? List four specific reasons |
1. Immuno supression (HIV or malaria) 2. Burkitt's lymphoma is EBV-2 serotype 3. C-Myconocogenic sometimes put in fornt of immunoglobulin genes in BUrkitt's lymphoma 4. P53 protooncogene sometimes turned off in Burkitt's lymphoma 5. Translocation of hcromosme 14 to 22 in Burkitt's lymphomia. |
Influenza virus can resort in an intermediate host. ; a) Explain in detail hos this reassortment of the following two viruses can occur in teh intermediate host, and the outcome: H3N2 and H5N1 ; b) Explain why this is important |
A) The intermediate host is usually a pig, which is an animal that can get both forms of influenza (ex) it can get the fomr of influenza that birds can get, but no pass it on to humans, and the forms that humans can get and not pass to birds. If a pig is infected with a strain from a bird and a strain from a human of the same t..? ontigenic shifts between thos viruses can occur. This happens when the viruses uncoat and go through the maturation phase. Here the neuraminidose and hemagluttinum peptomers can go from virus to virus. So you could have an H2V2 strain from a bird and an h5N1 strain that only infects humans and pigs. But in the end you could get a H3N1 or a H5N2 strain that could possibly affect humans. So in essence you oculd get a virus that has the potential to infect humans, and this has some extremely strong virulent factors that if picked up from a bird form, this kindof shifting around is what could possibly create a strain of H5N! that oculd pass from human to human potentially. ; b) lead to an epidemic or a pandemic. |
| Know how to complete a one-step growth curve graph of viruses. indicate where the 5 teps in the viral lifecyle occur. |
