Virology Multiple Choice Questions & Answers (MCQs) focuses on “HIV and AIDS”.
1. HIV-1 was first known as ___________
a) HHV
b) LAV
c) HSV
d) EBV
Answer: b
Clarification: HIV-1 was first known as lymphocyte-associated virus (LAV) or human T cell lymphocyte virus type 3 (HTLV-3). In 1985 a virus new to science, HIV-1 was isolated. AIDS was recognized before the virus that was responsible for them.
2. Which of the following therapy is used to halt HIV replication?
a) Gene therapy
b) Chemotherapy
c) HAART therapy
d) Physiotherapy
Answer: c
Clarification: HAART is a highly active anti-retrovirus therapy that is used to halt the HIV replication and progression to AIDS. In this therapy, a combination of two nucleoside analogs and a protease inhibitor is remarkably successful in halting virus replication.
3. HAART was discovered in __________
a) 1998
b) 1999
c) 1994
d) 1995
Answer: c
Clarification: HAART has been used since 1994. It is a successful therapy for halting the virus replication but it is an expensive therapy and this has restricted it largely to developed countries and overall less than 12% of people receive HAART.
4. HIV-1 is a member of __________ family.
a) retroviridae
b) arenaviridae
c) filoviridae
d) flaviviridae
Answer: a
Clarification: HIV-1 is a typical member of the lentivirus genus of the retroviridae family. HIV-1 causes over 99% of HIV infections, is globally dispersed and is usually fatal. They infect several different vertebrate species.
5. Which of the following member of the lentivirus family causes pneumonia?
a) HIV-1
b) HIV-2
c) Visna-Maedi
d) Bovine immunodeficiency
Answer: c
Clarification: Visna-Maedi is a typical member of the lentivirus subfamily that causes pneumonia or other chronic diseases. It is also caused by Streptococcus pneumonia, which is a bacterium.
6. Which of the following member of the lentivirus family causes anemia?
a) HIV-2
b) Visna-Maedi
c) Bovine immunodeficiency
d) Anemia
Answer: d
Clarification: Equine is a member of the lentivirus family that causes anemia. It also causes weight loss, recurrent fever, and little immunosuppression. The host of the virus is the horse and the main target cell is macrophage.
7. Tat _________
a) upregulates translation
b) downregulates translation
c) upregulates transcription
d) downregulates transcription
Answer: c
Clarification: Tat is an RNA-binding protein and it binds to the TAR element, which is a sequence in the nascent RNA that is encoded just downstream from the transcription start site and upregulates the transcription by increasing the processivity of RNA polymerase II.
8. Which of the following is a pleiotropic regulator?
a) Vif
b) Vpr
c) Nef
d) Vpu
Answer: c
Clarification: Nef is a complex pleiotropic (multifunctional) regulator. It down-modulates cell surface expression of CD4 and MHC class I proteins and increases virus infectivity. It also enhances the spread of infection.
9. HIV is not transmitted through ____________
a) saliva
b) breast milk
c) vaginal fluids
d) blood
Answer: a
Clarification: HIV is not transmitted through saliva. However, there are chances of HIV transmission by open-mouth kissing, using needles contaminated with HIV and vertical transmission such as feeding breast milk.
10. HIV-1 is haploid.
a) True
b) False
Answer: b
Clarification: HIV-1 is diploid and contains two identical molecules of positive-sense ssRNA. Almost all the retroviruses are diploid and contain positive sense ssRNA. It is more pathogenic.
11. M-tropic viruses infect only CD4+ macrophages and not T cells.
a) True
b) False
Answer: b
Clarification: M-tropic viruses infect both CD4+ macrophages and T cells. M-tropic and T-tropic are isolates of HIV-1 that use CCR5 as a coreceptor. T-tropic infects CD4+ T cells and uses a CXCR4 coreceptor.