Question

AIDS is caused due to a ___(i)______that has RNA as the genetic material which undergoes ___(ii)____to form____(iii)______ inside the host cells.

• A. (i)-bacterium, (ii)-transcription, (iii)-DNA
• B. (i)-virus, (ii)-reverse transcription, (iii)-DNA
• C. (i)-bacterium, (ii)-reverse transcription, (iii)-DNA
• D. (i)-virus, (ii)-reverse transcription, (iii)-RNA

Answer 1

The correct option is B (i)-virus, (ii)-reverse transcription, (iii)-DNA

HIV (Human immunodeficiency virus) is the causative organism for an immunodeficiency syndrome known as AIDS or acquired immunodeficiency syndrome.

HIV is usually transmitted either by having sexual contact with an infected person or by
transfusion of contaminated blood and blood products or by sharing
infected needles as in the case of intravenous drug abusers or from
infected mother to her child through the placenta.

Upon infection, the virus attacks the macrophages and helper T cells of the body and destroys them. Due to this, the immune system of an AIDS patient is severely and progressively weakened with time, the patient becomes vulnerable to infections which otherwise could have been easily overcome and are normally harmless.

HIV is a retrovirus having two single-stranded RNA molecules, each associated with a reverse transcriptase molecule. The reverse transcriptase enzyme catalyses the conversion of its RNA strand into a double-stranded DNA in the host cytoplasm.

The viral DNA integrates itself into the host genome and directs the infected cells to produce virus particles.