Human Immunodeficiency Virus (HIV)

Ans. is ‘a’ i.e., HIV & ‘b’ i.e., HTLV 

• Retroviruses contain an RNA genome and an RNA-directed DNA polymerase (reverse transcriptase). Both HIV and HTLV are Oncogenic reterovirus

Ans. is ‘a’ i.e., GAG

Ans. is ‘d’ i.e., All of the above

Ans. is ‘d’ i.e., Neutrophil

Ans. is ‘a’ i.e., Sentinel surveillance 

o Sentinel surveillance in India is done in national AIDS control programme.

Ans. A: CD4 cells

CD4 is a primary receptor used by HIV-1 to gain entry into host T cells.

HIV-1 attaches to CD4 with a protein in its viral envelope known as gp120.

The binding to CD4 creates a shift in the conformation of gp120 allowing HIV-1 to bind to two other surface receptors on the host cell, the chemokine receptors CCR5 or CXCR4, depending on whether HIV is infecting a macrophage or T-helper cell.

Following a structural change in another viral protein (gp41), HIV inserts a fusion peptide into the host cell that allows the outer membrane of the virus to fuse with the cell membrane.

HIV infection leads to a progressive reduction in the number of T cells possessing CD4 receptors. Therefore, medical professionals refer to the CD4 count to decide when to begin treatment for HIV-infected patients.

Ans. D i.e. All of the above

HIV virus

• It is composed of two copies of positive single-stranded RNA that codes for the virus’s nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein p24.
• The single-stranded RNA is tightly bound to nucleocapsid proteins, p7, and enzymes needed for the development of the virion such as reverse transcriptase, proteases, ribonuclease and integrase.
• A matrix composed of the viral protein p17 surrounds the capsid ensuring the integrity of the virion particle.

Ans. B: Double stranded DNA virus

HIV belongs to the lentivirus subgroup of the family retroviridae.

HIV is a spherical, enveloped virus. The genome is diploid, composed of two identical single-stranded, positive sense RNA copies.

The human immunodeficiency virus (HIV) like many other viruses, stores its genetic information as RNA rather than as DNA (most other living things use DNA).

In association with viral RNA is the reverse transcriptase enzyme which is a characteristic feature of retroviruses.

When HIV enters a human cell, it releases its RNA, and an enzyme called reverse transcriptase makes a DNA copy of the HIV RNA. The resulting HIV DNA is integrated into the infected cell’s DNA. This process is the reverse of that used by human cells, which make an RNA copy of DNA. Thus, HIV is called a retrovirus, referring to the reversed (backward) process. Other RNA viruses (such as polio, influenza, or measles), unlike retroviruses, do not make DNA copies after they invade cells. They simply make RNA copies of their original RNA.

Some types of white blood cells called CD4+ lymphocytes

HIV is highly mutable virus, unlike HTLV.

Ans:A.