Question

HIV is a

• A. DNA virus
• B. RNA virus
• C. Paramyxo virus
• D. Retrovirus

Hint:

Retroviruses, like HIV, have RNA genomes that are reverse transcribed into DNA once inside host cells.

Answer 1

The Correct Option is D

Step 1: Understanding HIV.
HIV (Human Immunodeficiency Virus) is a retrovirus. Retroviruses are RNA viruses that use reverse transcription to convert their RNA genome into DNA once inside a host cell. This DNA then integrates into the host cell's genome.
Step 2: Analyzing the options.
(A) DNA virus: This is incorrect as HIV is an RNA virus, not a DNA virus.
(B) RNA virus: While HIV is an RNA virus, it is specifically a retrovirus, which is a subclass of RNA viruses.
(C) Paramyxo virus: Paramyxoviruses are a different group of RNA viruses, unrelated to HIV.
(D) Retrovirus: Correct — HIV is a retrovirus, which is a type of RNA virus that replicates by reverse transcription.
Step 3: Conclusion.
The correct answer is (D) Retrovirus as HIV is a retrovirus.

Answer 2

We can work this out by first sorting the options into genetic-material families, then narrowing down to the specific type HIV belongs to.

1. DNA virus: HIV's genome is made of RNA, not DNA, so it cannot be placed in this category at all.
2. RNA virus: This is true in a broad sense - HIV does carry an RNA genome - but this label alone doesn't capture HIV's most distinctive feature, which is how it replicates.
3. Paramyxo virus: Paramyxoviruses (such as those causing measles or mumps) are a separate RNA virus family that replicates directly using RNA-dependent RNA polymerase; they never convert their genome into DNA, so this family does not describe HIV.
4. Retrovirus: HIV carries the enzyme reverse transcriptase, which copies its RNA genome into DNA that then integrates into the host cell's chromosome. This "reverse" flow of genetic information (RNA to DNA) is the defining feature of a retrovirus, and it is unique to HIV among the four choices.

Since HIV's defining biological feature is this RNA-to-DNA reverse transcription step, the most precise and complete classification is retrovirus.

Therefore, the correct answer is Retrovirus.