GATE 2021 BT – Question 11
Coronavirus genome consists of
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Correct answer: (D) positive-sense single-stranded RNA
Explanation
Coronaviruses (such as SARS-CoV-2, MERS-CoV and SARS-CoV) are enveloped viruses with a large **single-stranded RNA** genome of about 30 kb.
The RNA is of **positive sense**: it has the same polarity as mRNA, so after entry it can be translated directly by host ribosomes to make the replicase proteins.
- Double-stranded DNA: poxviruses, herpesviruses. ✗
- Double-stranded RNA: reoviruses, rotaviruses. ✗
- Negative-sense ssRNA: influenza virus, rabies virus. ✗
Answer **positive-sense single-stranded RNA** (D).