Which of the following best describes the morphology and genome organization of rabies virus?

Question

Accepted Answer

B. Enveloped, negative-sense single-stranded RNA virus with a helical nucleocapsid. ## Rabies Virus Structure

**Key Point:** Rabies virus is a **bullet-shaped, enveloped virus** belonging to the genus *Lyssavirus* within the family *Rhabdoviridae*.

### Genome Organization
- **Genome type:** Negative-sense, single-stranded RNA (−ssRNA)
- **Genome size:** ~11.9 kb
- **Gene order:** 3'–N–P–M–G–L–5' (five structural genes)
  - **N:** Nucleoprotein
  - **P:** Phosphoprotein (cofactor for RNA polymerase)
  - **M:** Matrix protein
  - **G:** Glycoprotein (spike protein; critical for cell entry and immune response)
  - **L:** RNA-dependent RNA polymerase (RdRp)

### Morphological Features
| Feature | Detail |
| --- | --- |
| **Shape** | Bullet-shaped (characteristic) |
| **Envelope** | Yes; derived from host cell plasma membrane |
| **Nucleocapsid** | Helical (ribonucleoprotein complex) |
| **Spike proteins** | Trimeric G protein spikes on envelope |
| **Size** | 70–80 nm × 100–150 nm |

**High-Yield:** The helical nucleocapsid within a bullet-shaped envelope is pathognomonic for rabies virus and distinguishes it from other rhabdoviruses.

**Clinical Pearl:** The G protein is the only surface antigen and the primary target of neutralizing antibodies; it is also the main determinant of neurotropism.

Answer

A. Enveloped, double-stranded DNA virus with linear genome

Answer

C. Non-enveloped, negative-sense single-stranded RNA virus with cubic symmetry

Answer

D. Non-enveloped, positive-sense single-stranded RNA virus with icosahedral symmetry

Which of the following best describes the morphology and genome organization of rabies virus?

Explanation

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