Virus consists of?

HPSSC Staff Nurse - 2021

Microbiology

Easy

Appeared in: HPSSC Staff Nurse - 2021

Explanation

The correct option describes the fundamental components of all viruses.
A complete virus particle, or virion, is composed of a nucleic acid core (its genome) and a protein coat (the capsid).
The nucleic acid can be either DNA or RNA, making 'nucleic acid' the general term.
The protein capsid protects the genetic material and helps in attaching to a host cell.
This combination of a protein coat and a nucleic acid genome is the minimum requirement for a particle to be classified as a virus.

Option A: This option is incomplete. A virus is not just made of protein; it must contain genetic material (nucleic acid) to replicate.
Option B: This option is incomplete. The nucleic acid (genetic material) of a virus must be protected by a protein coat called a capsid.
Option C: This option is too specific and therefore incorrect as a general definition. While many viruses (like influenza and HIV) use RNA as their genetic material, many others (like herpesviruses and adenoviruses) use DNA.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Basic structure and composition of a virus as background academic context rather than a clinical decision trigger.
Understanding viral structure is crucial for infection control. Enveloped viruses (e.g., Influenza, HIV, Coronaviruses) have a lipid membrane that is easily disrupted by soaps, detergents, and alcohol-based hand sanitizers, making them relatively easy to inactivate.
Non-enveloped viruses (e.g., Norovirus, Rotavirus, Hepatitis A) lack this lipid layer and are much more resistant to disinfectants. This is why thorough handwashing with soap and water is more effective than hand sanitizer for preventing the spread of infections like norovirus.
What if? - If a patient has gastroenteritis caused by Norovirus (a non-enveloped virus), the nurse must emphasize that alcohol-based hand rubs are insufficient. The primary infection control measure is meticulous handwashing with soap and water, along with surface disinfection using a bleach-based solution.

How to Approach the Question

First, identify the core question. The question asks for the fundamental components of a virus.
Recall the definition of a virus: an infectious agent consisting of genetic material and a protein coat.
Evaluate each option based on this definition.
Option A ('Protein') and Option B ('Nucleic acid') are incomplete as they each describe only one of the two essential components.
Option C ('Protein and RNA') is too specific. While true for RNA viruses, it excludes DNA viruses.
Option D ('Protein and Nucleic acid') is the most accurate and general description, as 'nucleic acid' covers both DNA and RNA. This is the best fit.

Concept Tested & Keywords

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