Question

HIV has a protein coat and a genetic material which is:
(a) ssDNA
(b) dsDNA
(c) ssRNA
(d) dsRNA

Answer 1

HIV or human immunodeficiency virus belongs to a family of Lentiviruses. Most of the viruses of this family have RNA as their sole genetic material and it is a single-stranded, positive-sense, enveloped RNA molecule.

Complete step by step answer:
Viruses are small, non-living parasites, which cannot replicate outside of a host cell. The genetic material of a virus is either DNA or RNA based on which the viruses are classified into 4 groups.
ssDNA viruses – The viruses whose genetic material is a single-stranded DNA molecule. e.g. Canine parvovirus
dsDNA viruses - The viruses whose genetic material is a double-stranded DNA molecule. e.g. Cytomegalovirus
ssRNA viruses - The viruses whose genetic material is a single-stranded RNA molecule. e.g. HIV and Human rhinovirus
dsRNA - The viruses whose genetic material is a double-stranded RNA molecule. e.g. Rotavirus.
HIV virus which is responsible for AIDS or acquired immune deficiency syndrome in humans is an ssRNA virus i.e. its genetic material is a single-stranded RNA molecule. It is a retrovirus which severely impairs the immune function in humans by affecting essential components such as CD4 T cells, Macrophages, and dendritic cells.
When the virus gains entry into the host cell the viral genome i.e. ssRNA molecule undergoes reverse transcription thereby forming a dsDNA molecule. This dsDNA now integrates into the host cell’s genome and starts replicating with the host DNA. Ultimately, HIV causes AIDS by depleting CD4 T cells.
So, the correct answer is ‘ssRNA’.

Note: HIV causes Acquired immunodeficiency syndrome. It is confirmed when CD4 T cell counts drop to 200 cells per microlitre in blood. As the immune system of the host is compromised, a variety of infections occur in the lifetime. This disease can only be prevented or prolonged if infected but it cannot be cured completely.