Questions and Answers
What is the definition of a virus?
A submicroscopic, parasitic, filterable agent consisting of nucleic acid: DNA or RNA surrounded by a protein coat.
What is the definition of a bacterium?
Prokaryotic organism characterized by peptidoglycan cell walls.
What is a viral species?
Group of viruses sharing the same genetic information and ecological niche.
What is virology?
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Which of the following are general characteristics of viruses? (Select all that apply)
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What is the protein coat of a virus called?
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What is the capsid made up of?
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What determines the host range of a virus?
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The capsid is made up of __________ and surrounds ________________.
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What is the envelope of a virus made up of?
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Some enveloped viruses are covered in __________.
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What are non-enveloped viruses known for?
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What is tissue tropism?
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What is the smallest virus?
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Bacteriophages enter the cell.
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What is a virion?
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What is a helical virus and provide an example.
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What is a polyhedral virus and provide an example.
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Enveloped viruses are typically __________, an example is __________.
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What are plaques?
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What is herpesviridae?
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What is Picornaviridae?
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What is Retroviridae?
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What is reverse transcriptase?
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What are the 7 groups of genome-based virus classification? (Select all that apply)
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What is a dsDNA virus and give an example.
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What is an ssDNA virus and give an example.
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What is a dsRNA virus and give an example.
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What is a (+)ssRNA virus and give an example.
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What is a (-)ssRNA virus and give an example.
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What is an ssRNA-RT virus and give an example.
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Give an example of a dsDNA-RT virus.
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Viral envelopes closely resemble __________.
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Viruses must be grown in __________.
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of plaques in a lawn growth is equivalent to ______.
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Animal viruses can be cultured in: (Select all that apply)
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Viruses can be identified by: (Select all that apply)
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What does serological testing detect in identifying viruses?
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What is viral multiplication?
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Outside the cell, viruses are __________.
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What are the two types of bacteriophage multiplication? (Select all that apply)
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What is the lytic cycle?
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What are the stages of the lytic cycle?
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What happens during the attachment stage of the lytic cycle?
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What occurs during the penetration stage of the lytic cycle?
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What does biosynthesis entail in the lytic cycle?
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What is maturation in the lytic cycle?
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What happens during the release stage of the lytic cycle?
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How do some animal viruses exit the host cell?
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What are the stages of the lysogenic cycle?
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What occurs during the attachment stage of the lysogenic cycle?
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What happens during the penetration stage of the lysogenic cycle?
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What is recombination in the lysogenic cycle?
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What happens during the cell division stage of the lysogenic cycle?
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What might happen during the lysogenic cycle?
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What is a prophage?
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Place in order found in the host cell from a bacteriophage: 1: capsid protein 2: infective phage particles 3: phage nucleic acid.
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All viruses have a __________.
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Bacteriophages never have an __________.
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The most basic virion structure is ______________.
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What do RNAse and DNAse enzymes do?
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What is a provirus?
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What is the genus responsible for causing HIV/Aids?
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What is oncology?
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What is the difference between benign and malignant tumors?
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What are three important characteristics of cancer cells? (Select all that apply)
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What is carcinoma?
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What is sarcoma?
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What happens to the genetic material of oncogenic viruses?
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What is an oncogenic virus?
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What is an oncogene?
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What is a proto-oncogene?
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What is a tumor suppressor gene?
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What are the two genes that regulate the cell cycle? (Select all that apply)
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What type of virus is a cancer inducing virus?
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Name the one RNA virus that can cause cancer.
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What do activated oncogenes do?
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What does transformation regarding viruses and cancer mean?
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What is a tumor specific transplantation antigen (TSTA)?
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What is an example of an oncogenic DNA virus?
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What is another example of an oncogenic DNA virus?
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What is an example of an oncogenic DNA virus that affects AIDS patients?
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What is an example of an oncogenic DNA virus that can cause Burkitt's Lymphoma?
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What is an example of an oncogenic RNA virus?
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What is another example of an oncogenic RNA virus?
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How can proto-oncogenes be activated to become oncogenes and cause cancer? (Select all that apply)
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What is a latent infection?
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What is a chronic infection?
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Give an example of a latent infection.
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Give an example of a chronic infection.
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What is a prion?
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How can prions be transmitted?
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What is the difference between encephalopathy and encephalitis?
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What are causes of spongiform encephalopathy? (Select all that apply)
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What is PrPc?
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What is PrPsc?
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Study Notes
Virus Characteristics
- A virus is a submicroscopic, parasitic agent composed of nucleic acid (DNA or RNA) surrounded by a protein coat (capsid).
- Obligatory intracellular parasites depend on host cells for replication.
- They can pass through bacterial filters, indicating their small size.
- Viruses may have an envelope originating from a host cell's membrane, and they often exhibit tissue specificity.
Virus Structure
- The capsid consists of protein subunits called capsomeres and encases the viral nucleic acid.
- Envelopes are composed of a phospholipid bilayer and may contain spikes made of carbohydrate-protein complexes that aid in host attachment.
- Non-enveloped viruses are more resilient to environmental factors.
Virus Types and Examples
- Helical viruses (e.g., Rabies, Ebola) appear as long rods, while polyhedral viruses (e.g., Herpes Simplex Virus, Poliovirus) have many sides.
- Enveloped viruses are generally spherical, exemplified by Herpes Simplex Virus.
- Varsity of viruses include ssRNA (e.g., Picornavirus) and dsDNA viruses (e.g., Herpesvirus, Adenovirus).
Viral Multiplication Phases
- Viruses must be grown in living cells, as they are inert outside a host.
- Two primary multiplication cycles for bacteriophages exist: lytic (results in cell lysis) and lysogenic (integrates viral DNA into host DNA).
- In the lytic cycle, stages include attachment, penetration, biosynthesis, maturation, and release of new virions.
Cancer and Oncogenic Viruses
- Oncogenic viruses can induce tumor formation by integrating their genetic material into the host DNA.
- Key characteristics of cancer cells include rapid division, loss of anchoring and inhibition of contact, leading to metastasis.
- Oncogenic DNA viruses include Papilloma Virus (HPV, causes cervical cancer) and Hepatitis B (liver cancer).
- HIV is a notable RNA virus associated with cancer induction.
Prions Overview
- Prions are infectious particles consisting solely of protein, characterized by abnormal folding.
- They can be inherited or transmitted through ingestion, surgeries, or transplants.
- Prion diseases, like Creutzfeldt Jakob Disease and Mad Cow Disease, cause spongiform encephalopathies resulting in brain degeneration.
Additional Concepts
- Latent infections, like those caused by herpes viruses, persist without symptom production for long periods.
- Chronic infections, exemplified by AIDS/HIV, develop slowly and can recur.
- Proto-oncogenes regulate normal cell division; activation by factors like carcinogens or viral infections can transform them into oncogenes, which lead to cancer.
Research & Testing
- Viruses are identified using cytopathic effects, serological testing (detects antibodies), and nucleic acid analysis.
- The presence of tumor-specific transplantation antigens can signal transformed cells due to oncogenic viruses.
Summary
- Viruses and prions represent unique classes of infectious agents, each with distinct structures, multiplication mechanisms, and implications for health, especially in relation to cancer and chronic diseases. Understanding their characteristics aids in advancements in virology and treatment options.
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Description
Explore key definitions and concepts related to viruses and prions in this flashcard quiz based on Chapter 13 of Microbiology. Learn about the characteristics of viruses, bacteria, and viral species while enhancing your understanding of microbiological principles.