Question

During HIV infection, which sequence correctly represents the events inside host cells?

• A. Reverse transcription \(\rightarrow\) RNA synthesis \(\rightarrow\) Integration
• B. Integration \(\rightarrow\) Reverse transcription \(\rightarrow\) Viral protein synthesis
• C. Reverse transcription \(\rightarrow\) Integration into host DNA \(\rightarrow\) Viral replication
• D. Viral replication \(\rightarrow\) Integration \(\rightarrow\) Reverse transcription

Hint:

Retroviruses contain RNA and use reverse transcriptase to synthesize DNA inside host cells.

Answer 1

The Correct Option is C

Human Immunodeficiency Virus (HIV) is a retrovirus responsible for causing AIDS (Acquired Immunodeficiency Syndrome). HIV primarily attacks helper T-lymphocytes of the immune system. Unlike most organisms that convert DNA into RNA, retroviruses possess RNA as genetic material and use a special enzyme called reverse transcriptase. The sequence of events during HIV infection is as follows:
• HIV enters the host helper T-cell.
• Viral RNA is released into the cytoplasm.
• Reverse transcriptase synthesizes complementary DNA from viral RNA. This process is called reverse transcription.
• The newly formed viral DNA enters the nucleus.
• Viral DNA integrates into the host chromosome and becomes a provirus.
• Host cellular machinery synthesizes viral RNA and proteins.
• New viral particles are assembled and released. Thus, the correct sequence is: \[ \text{Reverse transcription} \rightarrow \text{Integration into host DNA} \rightarrow \text{Viral replication} \] Option analysis:
• Option (A): Incorrect because integration occurs before synthesis of new viral RNA.
• Option (B): Incorrect because integration cannot occur before formation of viral DNA.
• Option (C): Correct
• Option (D): Incorrect sequence Therefore: \[ \boxed{\text{(C)}} \]