Hepatitis D virus (HDV) requires HBV coinfection because HDV:
- A Requires HBsAg as its own envelope protein to assemble and spread ✓
- B Uses HBV polymerase for replication of its own RNA genome
- C Requires HBcAg to package the HDV ribonucleoprotein
- D Needs HBV-encoded HBeAg for its own protein synthesis
Correct answer: A. Requires HBsAg as its own envelope protein to assemble and spread
Explanation
HDV is a defective RNA virus (virusoid) that encodes only the delta antigen (HDAg); it depends entirely on HBV for its envelope because HDV particles are coated with HBsAg borrowed from HBV — without HBsAg, HDV cannot form infectious virions. HDV uses its own RNA-dependent RNA polymerase activity (via cellular RNA polymerase II/III with HDAg) for replication, not HBV polymerase. HBcAg packages the HBV nucleocapsid; HDV packages its own HDAg. HBeAg is a secreted HBV protein with no role in HDV protein synthesis.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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