Podcast
Questions and Answers
Viruses exhibit all the following except ______.
Viruses exhibit all the following except ______.
Host cells of viruses include ______.
Host cells of viruses include ______.
Viruses ______.
Viruses ______.
Viral capsids are made from subunits called ______.
Viral capsids are made from subunits called ______.
Signup and view all the answers
Helical and icosahedral are terms used to describe the shape of a viral ______.
Helical and icosahedral are terms used to describe the shape of a viral ______.
Signup and view all the answers
A/an _____ is the protein shell around the nucleic acid core of a virus.
A/an _____ is the protein shell around the nucleic acid core of a virus.
Signup and view all the answers
One of the principal viral capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a/an _____ capsid.
One of the principal viral capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a/an _____ capsid.
Signup and view all the answers
A naked virus only has a/an ______.
A naked virus only has a/an ______.
Signup and view all the answers
Which of the following is not a typical capsid shape?
Which of the following is not a typical capsid shape?
Signup and view all the answers
All of the following pertain to virus envelopes except ______.
All of the following pertain to virus envelopes except ______.
Signup and view all the answers
Viral spikes ______.
Viral spikes ______.
Signup and view all the answers
The core of every virus particle always contains ______.
The core of every virus particle always contains ______.
Signup and view all the answers
Which of the following is not associated with every virus?
Which of the following is not associated with every virus?
Signup and view all the answers
Viral nucleic acid types include which of the following?
Viral nucleic acid types include which of the following?
Signup and view all the answers
Reverse transcriptase synthesizes ______.
Reverse transcriptase synthesizes ______.
Signup and view all the answers
A negative RNA virus must first ______.
A negative RNA virus must first ______.
Signup and view all the answers
Viruses with _____-sense RNA contain the correct message for translation, while viruses with _____-sense RNA must first be converted into a correct message.
Viruses with _____-sense RNA contain the correct message for translation, while viruses with _____-sense RNA must first be converted into a correct message.
Signup and view all the answers
Classification of viruses into families involves determining all the following characteristics except ______.
Classification of viruses into families involves determining all the following characteristics except ______.
Signup and view all the answers
Which of the following represents a virus family name?
Which of the following represents a virus family name?
Signup and view all the answers
Which of the following is not a viral order in the classification system?
Which of the following is not a viral order in the classification system?
Signup and view all the answers
The correct sequence of events in viral multiplication is ______.
The correct sequence of events in viral multiplication is ______.
Signup and view all the answers
Viruses acquire envelopes around their nucleocapsids during ______.
Viruses acquire envelopes around their nucleocapsids during ______.
Signup and view all the answers
In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's _____.
In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's _____.
Signup and view all the answers
Host range is limited by ______.
Host range is limited by ______.
Signup and view all the answers
Oncogenic viruses include all the following except ______.
Oncogenic viruses include all the following except ______.
Signup and view all the answers
Which of the following is/are type(s) of cytopathic effects?
Which of the following is/are type(s) of cytopathic effects?
Signup and view all the answers
The envelope of enveloped viruses ______.
The envelope of enveloped viruses ______.
Signup and view all the answers
Viruses attach to their hosts via ______.
Viruses attach to their hosts via ______.
Signup and view all the answers
Viral tissue specificities are called ______.
Viral tissue specificities are called ______.
Signup and view all the answers
The process of dissolving the envelope and capsid to release the viral nucleic acid is ______.
The process of dissolving the envelope and capsid to release the viral nucleic acid is ______.
Signup and view all the answers
Which of the following occurs during assembly?
Which of the following occurs during assembly?
Signup and view all the answers
Mammalian viruses capable of starting tumors are ______.
Mammalian viruses capable of starting tumors are ______.
Signup and view all the answers
Persistent viruses that can reactivate periodically are ______.
Persistent viruses that can reactivate periodically are ______.
Signup and view all the answers
Which of the following is not a characteristic of a transformed cell?
Which of the following is not a characteristic of a transformed cell?
Signup and view all the answers
New, nonenveloped virus release occurs by ______.
New, nonenveloped virus release occurs by ______.
Signup and view all the answers
What structures are used by bacteriophages to attach to host cell receptors?
What structures are used by bacteriophages to attach to host cell receptors?
Signup and view all the answers
Which of the following is incorrect about prophages?
Which of the following is incorrect about prophages?
Signup and view all the answers
T-even phages ______.
T-even phages ______.
Signup and view all the answers
The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is ______.
The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is ______.
Signup and view all the answers
Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called ______.
Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called ______.
Signup and view all the answers
Uncoating of viral nucleic acid ______.
Uncoating of viral nucleic acid ______.
Signup and view all the answers
In transduction, the viral genome ______.
In transduction, the viral genome ______.
Signup and view all the answers
Lysogeny refers to ______.
Lysogeny refers to ______.
Signup and view all the answers
Viruses that infect bacteria are specifically called ______.
Viruses that infect bacteria are specifically called ______.
Signup and view all the answers
During lysogeny, an inactive prophage state occurs when the viral DNA is inserted into the host ______.
During lysogeny, an inactive prophage state occurs when the viral DNA is inserted into the host ______.
Signup and view all the answers
What type of phage enters an inactive prophage stage?
What type of phage enters an inactive prophage stage?
Signup and view all the answers
The activation of a prophage is called ______.
The activation of a prophage is called ______.
Signup and view all the answers
When a bacterium acquires a trait from its temperate phage, it is called ______.
When a bacterium acquires a trait from its temperate phage, it is called ______.
Signup and view all the answers
Which of the following will not support viral cultivation?
Which of the following will not support viral cultivation?
Signup and view all the answers
Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called ______.
Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called ______.
Signup and view all the answers
When a virus enters a host cell, the viral genes redirect the genetic and metabolic activities of the host cell.
When a virus enters a host cell, the viral genes redirect the genetic and metabolic activities of the host cell.
Signup and view all the answers
Viruses are used to produce vaccines for prevention of certain viral infections.
Viruses are used to produce vaccines for prevention of certain viral infections.
Signup and view all the answers
Viruses are considered ultramicroscopic because they range in size from 2 mm to 450 mm.
Viruses are considered ultramicroscopic because they range in size from 2 mm to 450 mm.
Signup and view all the answers
Study Notes
General Characteristics of Viruses
- Viruses lack metabolism, meaning they cannot carry out metabolic processes on their own.
- Viruses possess genetic material (either DNA or RNA) and have a definite shape.
- They are ultramicroscopic, unable to be seen clearly with light microscopes.
Host Cells
- Viruses infect a variety of host cells, including humans, animals, plants, fungi, bacteria, protozoa, and algae.
Virus Structure
- Viral capsids, which protect the genetic material of viruses, are composed of subunits called capsomeres.
- Capsids can have different shapes, with helical and icosahedral being the principal types.
- Naked viruses consist only of a nucleocapsid, which is a protein shell around the nucleic acid.
Virus Envelopes and Spikes
- Viral envelopes are acquired from host cell membranes during the release process.
- Enveloped viruses have spikes that assist in the recognition and attachment to host cells.
Nucleic Acid in Viruses
- The core of every virus contains either DNA or RNA, but not both.
- Viral nucleic acid can be double-stranded DNA, single-stranded DNA, double-stranded RNA, or single-stranded RNA.
Virus Classification
- Viral families are classified based on characteristics such as type of nucleic acid, type of capsid, presence of an envelope, and number of nucleic acid strands.
- Example of a virus family: Herpesviridae, which includes various herpesviruses.
Viral Multiplication Cycle
- The sequence of viral multiplication involves adsorption, penetration, uncoating, synthesis, assembly, and release of new viral particles.
- Most DNA viruses replicate in the host's nucleus, while RNA viruses typically replicate in the cytoplasm.
Host Range and Tropisms
- The range of hosts that a virus can infect is influenced by the type of receptors present on the host cell membrane.
Oncogenic Viruses
- Some viruses can lead to tumor formation and are referred to as oncoviruses (e.g., Papillomavirus, Hepatitis B virus).
- Persistent viruses can reactivate, causing alternating periods of activity and inactivity.
Bacteriophages
- Bacteriophages specifically infect bacteria and may enter a lysogenic phase, where their DNA integrates into the bacterial chromosome.
Cytopathic Effects
- Viruses can cause visible changes in host cells known as cytopathic effects, which include inclusions and multinucleated giant cells.
Prophages and Lysogeny
- Prophages are inactive viral DNA integrated into the bacterial genome during lysogeny.
- Induction refers to the activation of a prophage, resulting in lytic infection.
Viral Cultivation
- Viruses can be cultivated using live lab animals, embryonated bird eggs, primary cell cultures, and continuous cell cultures.
Notable Insights
- The process of uncoating releases viral nucleic acids and occurs after viral penetration.
- Viruses are utilized in vaccine production to prevent certain viral infections.
- Viruses are considered ultramicroscopic due to their extraordinarily small size, typically ranging from 20 nm to 300 nm, contradicting the erroneous size range of 2 mm to 450 mm.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of key concepts from Microbiology Chapter 6 with these flashcards. Explore the fascinating world of viruses, including their structure, host cells, and characteristics. Perfect for students looking to reinforce their learning and recall important information.
