This set of Virology Multiple Choice Questions & Answers (MCQs) focuses on “HIV and AIDS”.
1. HIV-1 was first known as ___________
Explanation: 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
c) HAART therapy
Explanation: 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 __________
Explanation: 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.
Explanation: 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?
d) Bovine immunodeficiency
Explanation: 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?
c) Bovine immunodeficiency
Explanation: 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
Explanation: 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?
Explanation: 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 ____________
b) breast milk
c) vaginal fluids
Explanation: 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.
Explanation: 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.
Explanation: 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.
Sanfoundry Global Education & Learning Series – Virology.
To practice all areas of Virology, here is complete set of 1000+ Multiple Choice Questions and Answers.
Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!