Corona Virus is an?

Appeared in: Hariyana-CHO-2021

Explanation

Coronaviruses are classified under the family Coronaviridae and are defined as RNA viruses.
Their genetic material consists of a single-stranded, positive-sense RNA molecule, often abbreviated as (+)ssRNA.
This (+)ssRNA can function directly as messenger RNA (mRNA) inside the host cell, allowing for immediate translation of viral proteins.
Well-known examples include SARS-CoV-2 (causes COVID-19), SARS-CoV, and MERS-CoV.

Option A: Coronaviruses do not contain DNA. Their genetic core is made of RNA.
Option C: A fundamental principle of virology is that a mature virion contains either DNA or RNA as its nucleic acid core, but never both.
Option D: This option is incorrect because options A and C are false.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Viral classification based on genetic material as background academic context rather than a clinical decision trigger.
The RNA-based genome of coronaviruses is replicated by an enzyme (RNA-dependent RNA polymerase) that lacks strong proofreading ability. This leads to a high mutation rate, facilitating the emergence of new variants with different characteristics of transmissibility, severity, and immune evasion.
The presence of a lipid envelope makes the virus vulnerable to disinfectants like soap and alcohol. These agents disrupt the envelope, inactivating the virus and forming the basis for effective hand hygiene protocols.
The development of mRNA vaccines (like those from Pfizer-BioNTech and Moderna) for COVID-19 was based on the virus's genetic sequence. These vaccines provide the host cells with the mRNA code for the spike protein, triggering an immune response without using the live virus.

How to Approach the Question

First, identify the core of the question: it asks for the type of nucleic acid in a Coronavirus.
Recall the basic classification of viruses into two major groups: DNA viruses and RNA viruses.
Remember the fundamental rule that a virus contains either DNA or RNA, but not both. This immediately eliminates the 'Both DNA & RNA' option.
Access your knowledge about major human pathogens. Coronavirus, influenza, and HIV are classic examples of RNA viruses.
Based on this knowledge, select 'RNA virus' as the correct classification.
Confirming that 'RNA virus' is correct makes 'DNA virus' and 'All of above' incorrect by default.

Concept Tested & Keywords

Q08IzOxyLn0rqzTP7J8wlr

E6 Microbiology Essentials Sastry 4e Part 1 p. 89-91

E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 225-227

E6 Medicine Harrison 22e Part 1 p. 1521-1523

Practise the full Hariyana-CHO-2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.