Problem 104 - Objective Biology for NEET

Question

Virus infected plants generally have (a) Single stranded DNA (b) Double stranded DNA (c) Double stranded RNA (d) Single stranded RNA

Step-by-Step Solution

Answer

The correct answer is (d) Single stranded RNA.

Step 1: Understanding the types of genetic material in viruses

First it is important to know that viruses can have either DNA or RNA as their genetic material. This could be either single or double stranded. They use this genetic material to infect the host organism and replicate within it.

Step 2: Identify Genetic Material

As per virology, most plant infecting viruses contain 'Single stranded RNA' as their genetic material. However, there are exceptions, but this is the most common type.

Key Concepts

Single Stranded RNA

Single stranded RNA (ssRNA) is a type of genetic material found in many viruses, especially those infecting plants. Unlike DNA, which is typically double-stranded, ssRNA consists of a single strand of nucleotides. This configuration allows ssRNA viruses to be highly adaptable and efficient in using the host cell's machinery for replication.
The single strand acts as a template during the process of replication, where it is either directly translated to produce viral proteins or converted into a complementary strand. These proteins help in building new virus particles and spreading the infection.
Here are some notable features:

• Most ssRNA viruses are quite flexible and can quickly evolve to adapt to environmental changes.
• The single-stranded nature means fewer repair mechanisms for mutations, which can lead to rapid genetic variations.

This rapid evolution can result in challenges in managing infections, as new strains can appear over time, potentially overcoming existing plant defenses.

Genetic Material in Viruses

Viruses are unique infectious agents due to their simplicity. Their genetic material is one of the key aspects that define how they function and propagate. Unlike most organisms that use double-stranded DNA as genetic material, viruses can have various types, such as:

• Single stranded DNA (ssDNA)
• Double stranded DNA (dsDNA)
• Single stranded RNA (ssRNA)
• Double stranded RNA (dsRNA)

Diverse genetic material types allow viruses to infect a broad range of host organisms, from bacteria to plants and animals. In the realm of plant virology, ssRNA is common because it allows viruses to hijack the plant cell machinery efficiently.
The virus inserts its genetic material into the host cells, initiating a process that redirects the cell’s functions towards producing new virus particles instead of its usual tasks. This manipulation is crucial to the viral life cycle and is heavily studied to understand how to protect plants from viral outbreaks. Understanding the type of genetic material can also help in devising strategies for disease management by targeting specific points in the viral replication cycle.

Virology

Virology is the scientific discipline that focuses on the study of viruses and their role in disease. It encompasses the structure, classification, and evolution of viruses, as well as how they interact with host organisms. When it comes to plant virology, one of the most important areas of study is how viruses infect plants and spread through them.
Plant virology is notable for tackling challenges like ensuring food security, since plant diseases can devastate crops. Virologists work to understand viral life cycles, transmission modes, and potential methods to control or eliminate infections.
Key points in virology include:

• Determining how viruses initiate infection and replicate within host cells.
• Studying genetic mutations and how they might lead to new strains.
• Developing vaccines and treatments to prevent viral infections.

By understanding these processes, researchers can develop better strategies for preventing and managing viral diseases in plants, ultimately protecting important food resources and supporting sustainable agriculture.