Question

Viruses which infect animals have (a) Single stranded RNA (b) Double stranded RNA (c) Double stranded DNA (d) Any of the above

Short answer

Viruses infecting animals can have any of the mentioned types of genetic material: Single Stranded RNA, Double Stranded RNA, Double Stranded DNA. So, the correct answer is (d) Any of the above.

Step-by-step solution

Understanding Virus Structure

Viruses are infectious particles that can only replicate inside a host organism. They are composed of a protein coat known as a capsid and genetic material, which can be either RNA or DNA. This genetic material can be single or double stranded.

Knowing Virus Varieties

There are viruses with different types of genetic material. For example, HIV is an example of a virus with single stranded RNA, Influenza A virus with double stranded RNA and Herpes simplex viruses with double stranded DNA.

Answering The Question

Given the above information, we can conclude that viruses infecting animals can have any of the mentioned types of genetic material: single stranded RNA, double stranded RNA, double stranded DNA

Key concepts

Virus Structure

Viruses are fascinating infectious agents, much smaller than bacteria, and are incapable of reproducing on their own. These tiny particles need to invade a living cell to multiply. This simple yet effective structure forms the basis of their ability to hijack cellular machinery. The primary components of a virus are its genetic material and a protein shell known as the capsid. The genetic material is either DNA or RNA and can be single or double stranded.

The capsid protects the viral genetic material and determines the virus's ability to infect host cells. Some viruses have an additional envelope made of lipids, derived from the host's cell membrane, which helps them evade the immune system. This structure leads to the categorization of viruses based on their genetic material and structural characteristics, making virus classification more straightforward.

Single Stranded RNA Viruses

Single stranded RNA (ssRNA) viruses have a genome comprised of ribonucleic acid (RNA) that exists as a single strand. This type of virus is quite prevalent and linked with many common diseases. An interesting aspect of ssRNA viruses is their ability to mutate rapidly, which presents challenges in vaccine development.

Some well-known ssRNA viruses include:

• HIV - the virus responsible for causing AIDS
• Influenza viruses - known for their yearly flu outbreaks
• Coronavirus - a group that includes the notorious COVID-19 virus

The variety among ssRNA viruses is massive, showcasing different modes of transmission and pathogenesis. This diversity necessitates advanced methods of diagnosis and treatment.

Double Stranded RNA Viruses

Double stranded RNA (dsRNA) viruses have RNA that is structured as two complementary strands, similar to the DNA in cells but utilizing RNA as its material. These viruses generally target specific groups of organisms, including plants, animals, and fungi. They tend to be less common in humans compared to ssRNA viruses but are significant in certain contexts.

Examples of dsRNA viruses include:

• Rotavirus - a significant cause of severe diarrhea in children
• Reoviruses - responsible for respiratory and gastrointestinal infections

DsRNA viruses can be quite stable due to their double-stranded nature, providing resilience against environmental stress. Despite their rarity in human disease, they pose major challenges in veterinary and agricultural settings.

Double Stranded DNA Viruses

Double stranded DNA (dsDNA) viruses contain a genome of double stranded deoxyribonucleic acid (DNA), akin to the genetic material found in human cells. This viral type is often more stable than RNA viruses due to its genomic configuration, granting them the ability to persist in the host for lengthy periods.

Key examples of dsDNA viruses include:

• Herpesviruses - causing conditions such as chickenpox, cold sores, and genital herpes
• Adenoviruses - commonly leading to respiratory illnesses
• Poxviruses - notorious for diseases like smallpox, which is now eradicated

The understanding of dsDNA viruses is crucial for developing long-lasting therapeutic and preventive measures, given their potential for latency and reactivation. Effective management of these viruses requires both acute treatment and strategies to prevent reactivation.