Q1. What are the characteristics of viruses?

Background

Topic: Viral Structure and Properties

This question tests your understanding of what makes viruses unique compared to other microorganisms, including their structure, replication, and dependence on hosts.

Key Terms:

• Virus: A non-cellular infectious agent.

• Capsid: Protein coat surrounding viral genetic material.

• Envelope: Lipid membrane present in some viruses.

• Obligate intracellular parasite: Requires a host cell to reproduce.

Step-by-Step Guidance

1. Consider the basic structure of viruses: Do they have cellular components like organelles or cytoplasm?

2. Think about the genetic material: Is it DNA, RNA, or both? How is it packaged?

3. Reflect on how viruses replicate: Can they reproduce on their own, or do they need a host cell?

4. Identify any unique features, such as the presence of an envelope or spikes for attachment.

Try solving on your own before revealing the answer!

Q2. How do viruses compare to bacteria?

Background

Topic: Microbial Differences

This question asks you to contrast viruses and bacteria in terms of structure, replication, and metabolic capabilities.

Key Terms:

• Bacteria: Prokaryotic cells with cellular machinery.

• Virus: Acellular, lacks metabolic machinery.

• Replication: How each reproduces.

Step-by-Step Guidance

1. List the structural differences: Do both have cell walls, membranes, or organelles?

2. Compare their genetic material: Is it always DNA, or can it be RNA?

3. Think about their ability to reproduce: Can bacteria divide independently? What about viruses?

4. Consider metabolic activity: Do viruses carry out metabolism?

Try solving on your own before revealing the answer!

Q3. What determines the virus host range?

Background

Topic: Viral Infection Specificity

This question explores what factors allow a virus to infect certain hosts or cell types.

Key Terms:

• Host range: The spectrum of hosts a virus can infect.

• Receptor: Molecule on host cell surface recognized by virus.

• Attachment: Initial step in viral infection.

Step-by-Step Guidance

1. Identify the role of viral surface proteins in recognizing host cell receptors.

2. Consider the compatibility between viral proteins and host cell receptors.

3. Think about other factors, such as host cell machinery and immune defenses.

Try solving on your own before revealing the answer!

Q4. What is a virion?

Background

Topic: Viral Structure

This question asks you to define the term "virion" and understand its significance in the viral life cycle.

Key Terms:

• Virion: Complete, infectious viral particle.

• Capsid: Protein shell.

• Envelope: Lipid layer (if present).

Step-by-Step Guidance

1. Recall the components that make up a virion.

2. Consider the role of the virion in transmission and infection.

3. Think about how the virion differs from other forms of the virus (e.g., inside the host cell).

Try solving on your own before revealing the answer!

Q5. How are viruses classified?

Background

Topic: Viral Taxonomy

This question tests your knowledge of the criteria used to group viruses into families, genera, and species.

Key Terms:

• Classification: Grouping based on shared characteristics.

• Genome type: DNA or RNA, single or double stranded.

• Capsid symmetry: Shape of protein coat.

• Envelope presence: Whether virus has a lipid envelope.

Step-by-Step Guidance

1. Identify the main criteria used for classification (genetic material, structure, etc.).

2. Consider how genome type affects classification.

3. Think about the role of capsid shape and envelope in taxonomy.

Try solving on your own before revealing the answer!

Q6. Why must viruses be grown in living cells for culturing?

Background

Topic: Viral Cultivation

This question examines why viruses cannot be cultured on standard media like bacteria.

Key Terms:

• Obligate intracellular parasite: Requires host cell for replication.

• Cell culture: Growing cells in laboratory conditions.

Step-by-Step Guidance

1. Recall the basic requirements for viral replication.

2. Consider what viruses lack compared to bacteria (e.g., metabolic machinery).

3. Think about why living cells provide the necessary environment for viral reproduction.

Try solving on your own before revealing the answer!

Q7. What methods are used to identify viruses?

Background

Topic: Viral Detection and Diagnosis

This question tests your knowledge of laboratory techniques used to detect and identify viruses.

Key Terms:

• Serology: Detection of antibodies or antigens.

• PCR: Polymerase chain reaction for viral nucleic acids.

• Electron microscopy: Visualization of viral particles.

Step-by-Step Guidance

1. List common laboratory methods for viral identification.

2. Consider the advantages and limitations of each method.

3. Think about which methods are used for different types of viruses.

Try solving on your own before revealing the answer!

Q8. Compare the lytic and lysogenic cycles.

Background

Topic: Viral Replication Strategies

This question asks you to distinguish between two major viral replication pathways in bacteria.

Key Terms:

• Lytic cycle: Virus replicates and destroys host cell.

• Lysogenic cycle: Viral genome integrates into host DNA.

• Prophage: Integrated viral DNA in lysogenic cycle.

Step-by-Step Guidance

1. Describe the steps of the lytic cycle (attachment, entry, replication, assembly, release).

2. Outline the lysogenic cycle (integration, dormancy, induction).

3. Compare the outcomes for the host cell in each cycle.

Try solving on your own before revealing the answer!

Q9. How does lysogeny influence the evolution of bacteria?

Background

Topic: Viral Impact on Bacterial Genetics

This question explores how the lysogenic cycle can affect bacterial populations and traits.

Key Terms:

• Lysogeny: Integration of viral DNA into bacterial genome.

• Prophage: Viral DNA in host genome.

• Horizontal gene transfer: Movement of genes between organisms.

Step-by-Step Guidance

1. Consider how prophage genes can alter bacterial traits (e.g., toxin production).

2. Think about the role of lysogeny in genetic diversity and evolution.

3. Reflect on how lysogeny can contribute to antibiotic resistance or virulence.

Try solving on your own before revealing the answer!

Q10. What is the difference between DNA and RNA viruses?

Background

Topic: Viral Genome Types

This question tests your understanding of how the type of nucleic acid affects viral replication and classification.

Key Terms:

• DNA virus: Contains DNA as genetic material.

• RNA virus: Contains RNA as genetic material.

• Replication: How each type copies its genome.

Step-by-Step Guidance

1. Identify the main differences in genetic material (DNA vs. RNA).

2. Consider how replication mechanisms differ for each type.

3. Think about how these differences affect classification and disease.

Try solving on your own before revealing the answer!

Q11. What are the characteristics of prions?

Background

Topic: Non-Viral Infectious Agents

This question asks you to describe prions and how they differ from viruses and bacteria.

Key Terms:

• Prion: Infectious protein.

• Protein misfolding: Key to prion disease.

• No nucleic acid: Prions lack DNA/RNA.

Step-by-Step Guidance

1. Recall the basic structure of prions (protein only).

2. Consider how prions cause disease (misfolding, aggregation).

3. Think about how prions differ from viruses and bacteria in terms of replication and transmission.

Try solving on your own before revealing the answer!