Q1. What are the basic characteristics of a virus?

Background

Topic: Virology – Virus Structure and Properties

This question tests your understanding of what defines a virus, including its structure, replication, and how it differs from other microorganisms.

Key Terms:

• Virus

• Obligate intracellular parasite

• Capsid

• Nucleic acid (DNA or RNA)

• Envelope (optional)

Step-by-Step Guidance

1. Start by recalling that viruses are not considered living organisms because they cannot carry out metabolism or reproduce independently.

2. Identify the essential components of all viruses: genetic material (either DNA or RNA) and a protein coat called a capsid.

3. Consider additional features some viruses may have, such as a lipid envelope derived from the host cell membrane.

4. Think about how viruses replicate: they must infect a host cell and use the host's machinery to reproduce.

Try describing the basic characteristics of a virus before checking the answer!

Q2. What are the different parts of a virus? What is the bare minimum needed to make a virus?

Background

Topic: Virus Structure

This question focuses on identifying the structural components of viruses and understanding what is absolutely required for a virus to exist.

Key Terms:

• Capsid

• Nucleic acid

• Envelope

• Spikes

Step-by-Step Guidance

1. List the main structural components found in viruses (e.g., nucleic acid, capsid, envelope, spikes).

2. Determine which of these components are found in all viruses and which are only present in some.

3. Identify the absolute minimum components required for a virus to be infectious.

Try listing the parts and minimum requirements before revealing the answer!

Q3. What are the basic shapes and general structure of viruses? What is the difference between enveloped and non-enveloped viruses?

Background

Topic: Virus Morphology

This question tests your knowledge of the different shapes viruses can have and the structural differences between enveloped and non-enveloped viruses.

Key Terms:

• Helical

• Icosahedral

• Complex

• Envelope

• Naked (non-enveloped)

Step-by-Step Guidance

1. Recall the three main shapes of viruses: helical, icosahedral, and complex.

2. Describe the structural features of each shape.

3. Explain what an envelope is and how enveloped viruses acquire it.

4. Compare the properties of enveloped versus non-enveloped (naked) viruses, especially regarding stability and transmission.

Try explaining the shapes and differences before checking the answer!

Q4. What are all the possible variations of genetic material that can be found in a virus?

Background

Topic: Viral Genomes

This question is about the diversity of viral genetic material and how it differs from cellular organisms.

Key Terms:

• DNA virus

• RNA virus

• Single-stranded (ss)

• Double-stranded (ds)

• Positive-sense

• Negative-sense

Step-by-Step Guidance

1. List the types of nucleic acids that can serve as viral genomes (DNA or RNA).

2. For each type, note whether it can be single-stranded or double-stranded.

3. For RNA viruses, consider whether the RNA is positive-sense or negative-sense.

Try listing all possible variations before revealing the answer!

Q5. What is a bacteriophage?

Background

Topic: Virus-Host Specificity

This question asks you to define a specific type of virus and understand its host range.

Key Terms:

• Bacteriophage

• Phage

• Bacteria

Step-by-Step Guidance

1. Recall the definition of a bacteriophage and what organisms it infects.

2. Think about how bacteriophages differ from animal or plant viruses in terms of host specificity.

Try defining bacteriophage before checking the answer!

Q6. What is plaque and what causes plaque to form?

Background

Topic: Viral Cultivation and Detection

This question is about how viral infection is detected in a laboratory setting, especially with bacteriophages.

Key Terms:

• Plaque

• Lysis

• Host cell

Step-by-Step Guidance

1. Define what a plaque is in the context of a bacterial lawn on an agar plate.

2. Explain the process by which viruses cause plaques to form (e.g., lysis of host cells).

Try explaining plaque formation before revealing the answer!

Q7. What domains of life are susceptible to viral infections?

Background

Topic: Virus Host Range

This question tests your understanding of the breadth of viral infection across different domains of life.

Key Terms:

• Bacteria

• Archaea

• Eukarya

Step-by-Step Guidance

1. Recall the three domains of life: Bacteria, Archaea, and Eukarya.

2. Consider whether viruses can infect organisms in each domain.

Try listing the domains before checking the answer!

Q8. What is the difference between the lytic and lysogenic cycles?

Background

Topic: Viral Replication Strategies

This question is about the two main life cycles of bacteriophages and how they affect the host cell.

Key Terms:

• Lytic cycle

• Lysogenic cycle

• Prophage

• Lysis

Step-by-Step Guidance

1. Define the lytic cycle and describe what happens to the host cell during this process.

2. Define the lysogenic cycle and explain how it differs from the lytic cycle, especially regarding integration into the host genome.

3. Consider what triggers a switch from lysogenic to lytic cycle.

Try explaining the differences before revealing the answer!

Q9. What are the steps of the lytic cycle?

Background

Topic: Bacteriophage Replication

This question asks you to recall the sequence of events in the lytic replication cycle of a bacteriophage.

Key Terms:

• Attachment

• Penetration

• Biosynthesis

• Maturation

• Release

Step-by-Step Guidance

1. List the main steps of the lytic cycle in order.

2. Briefly describe what happens during each step (e.g., attachment to host, injection of genetic material, synthesis of viral components, assembly, and release).

Try listing and describing the steps before checking the answer!

Q10. What is the general reproductive cycle of animal viruses?

Background

Topic: Animal Virus Replication

This question is about the stages animal viruses go through to infect and replicate within host cells.

Key Terms:

• Attachment

• Penetration

• Uncoating

• Biosynthesis

• Maturation

• Release

Step-by-Step Guidance

1. List the general steps in the replication cycle of animal viruses.

2. Note any steps unique to animal viruses, such as uncoating.

3. Briefly describe what occurs during each step.

Try outlining the cycle before revealing the answer!

Q11. What is a viroid and a prion? How are they different from viruses?

Background

Topic: Subviral Infectious Agents

This question tests your understanding of infectious agents smaller than viruses and how they differ structurally and functionally from viruses.

Key Terms:

• Viroid

• Prion

• Proteinaceous infectious particle

• RNA

Step-by-Step Guidance

1. Define what a viroid is and what it is composed of.

2. Define what a prion is and its composition.

3. Compare both to viruses in terms of structure and replication.

Try explaining the differences before revealing the answer!

Q12. Why do viruses need to be grown in living cells? What different ways are used to grow viruses?

Background

Topic: Viral Cultivation

This question is about the requirements for viral replication and laboratory methods for growing viruses.

Key Terms:

• Obligate intracellular parasite

• Host cell

• Cell culture

• Embryonated eggs

• Animal models

Step-by-Step Guidance

1. Explain why viruses cannot replicate outside of living cells.

2. List the main laboratory methods used to grow viruses (e.g., cell cultures, embryonated eggs, live animals).

Try explaining the reasons and methods before revealing the answer!