Question

Virus contains (a) Protein (b) DNA (d) RNA (d) (a) and either (b) or (c)

Short answer

The correct answer to the question 'What does a virus contain?' is option (d) - (a) and either (b) or (c) – Protein and either DNA or RNA.

Step-by-step solution

Understanding Virus Composition

A virus is a tiny infectious agent that can only replicate inside the cells of another organism. They are made up of protein coat, called a capsid, and genetic material, which can be either Deoxyribonucleic Acid (DNA) or Ribonucleic Acid (RNA).

Identifying the Correct Answer

Looking at the options given, option (a) is correct as viruses contain Protein. Options (b) and (c) are partially correct as viruses contain either DNA (b) or RNA (c) but not necessarily both at the same time. Therefore, the most accurate response will be option (d) - (a) and either (b) or (c) – Protein and either DNA or RNA.

Key concepts

Protein Coat

All viruses have a protective outer layer known as the protein coat, or capsid. This coat is essential for the virus's survival and functionality. It is made from protein molecules, often arranged in a precise, repeating pattern that gives the virus its particular shape.
The protein coat serves several key roles:

• Provides structural support and shape to the virus.
• Protects the viral genetic material from damage.
• Helps the virus attach to host cells and initiate infection.

Without this coat, the virus could not effectively survive in external environments or spread infections.

Genetic Material

The genetic material of a virus encodes the necessary information for the virus's replication and function. Unlike cells, viruses do not have a complex set of organelles to sustain life, so they rely heavily on the genetic instructions within their genetic material.
Virus genetic material can be either:

• DNA (Deoxyribonucleic Acid) – typically found in more stable viruses.
• RNA (Ribonucleic Acid) – usually present in viruses that rapidly mutate, such as influenza.

This genetic material determines how the virus acts and evolves over time.

DNA

Some viruses contain DNA as their genetic material. DNA viruses generally store their information in double-stranded DNA, similar to the genetic material in human cells. This offers greater stability and resistance to mutations compared to RNA.
Key characteristics of DNA viruses include:

• Higher stability, making them less prone to mutation.
• A more reliable replication process, ensuring consistent characteristics across generations.
• Commonly causing persistent or long-lasting infections, such as herpes viruses.

Understanding the role and structure of DNA helps in developing targeted antiviral treatments.

RNA

Viruses that contain RNA have distinct characteristics from those with DNA. RNA viruses usually have single-stranded RNA as their genetic material, which allows for faster but less stable replication.
This results in:

• Rapid mutation rates, leading to high variability and adaptability.
• Challenges in vaccine development, as rapid changes can render vaccines less effective.
• Examples include influenza, HIV, and the virus responsible for COVID-19.

The high mutation rate of RNA viruses requires ongoing research to develop effective treatments and vaccines.