Podcast
Questions and Answers
What was the outcome of Chamberland's experiments with the tobacco mosaic virus?
What was the outcome of Chamberland's experiments with the tobacco mosaic virus?
- It resulted in a vaccine for tobacco plants.
- It showed that the paste could kill bacteria.
- It proved that bacteria are the cause of disease.
- It proved that viruses exist. (correct)
All viruses can be easily filtered out from any fluid.
All viruses can be easily filtered out from any fluid.
False (B)
What is the primary characteristic of obligate parasites?
What is the primary characteristic of obligate parasites?
Unable to grow outside of a living host.
Antibiotics do not kill __________.
Antibiotics do not kill __________.
Match each virus to its associated symptom or condition:
Match each virus to its associated symptom or condition:
What is a characteristic of an envelope virus?
What is a characteristic of an envelope virus?
Vaccination completely eliminated smallpox worldwide.
Vaccination completely eliminated smallpox worldwide.
What is the common cause of the common cold?
What is the common cause of the common cold?
What type of virus does HIV represent?
What type of virus does HIV represent?
The lytic cycle of a virus results in the replication of the virus without destroying the host cell.
The lytic cycle of a virus results in the replication of the virus without destroying the host cell.
Who was responsible for the first human viral disease diagnosis from an animal?
Who was responsible for the first human viral disease diagnosis from an animal?
The agent that kills viruses is known as a __________.
The agent that kills viruses is known as a __________.
Match the following viral characteristics with their descriptions:
Match the following viral characteristics with their descriptions:
What is the primary method of control for viruses like polio?
What is the primary method of control for viruses like polio?
Humans cutting down trees had no influence on the transmission of yellow fever.
Humans cutting down trees had no influence on the transmission of yellow fever.
The process by which a virus enters a host cell is called __________.
The process by which a virus enters a host cell is called __________.
What is a retrovirus?
What is a retrovirus?
DNA viruses replicate in the cytoplasm.
DNA viruses replicate in the cytoplasm.
Name one function of antiviral drugs.
Name one function of antiviral drugs.
The main purpose of __________ is to protect individuals and establish herd immunity.
The main purpose of __________ is to protect individuals and establish herd immunity.
Which of the following is NOT one of the requirements for effective vaccines?
Which of the following is NOT one of the requirements for effective vaccines?
Match the antiviral drugs with their specific function.
Match the antiviral drugs with their specific function.
What is a protein coat in viruses called?
What is a protein coat in viruses called?
Complex viruses have a simple structure.
Complex viruses have a simple structure.
What type of immunity involves B cells producing antibodies after exposure to specific antigens?
What type of immunity involves B cells producing antibodies after exposure to specific antigens?
Passive artificial immunity involves the natural transfer of antibodies from a mother to her infant.
Passive artificial immunity involves the natural transfer of antibodies from a mother to her infant.
What type of cells directly attack and kill diseased cells, including cancer cells?
What type of cells directly attack and kill diseased cells, including cancer cells?
Vaccines using dead or inactive pathogens are created by __________ the cells using heat or chemicals.
Vaccines using dead or inactive pathogens are created by __________ the cells using heat or chemicals.
Match the type of immunity with its definition:
Match the type of immunity with its definition:
Which cells release cytokines to activate B cells?
Which cells release cytokines to activate B cells?
What is the primary distinction between innate and adaptive immunity?
What is the primary distinction between innate and adaptive immunity?
Attenuated vaccines are made with weakened living pathogens.
Attenuated vaccines are made with weakened living pathogens.
Flashcards
Virus
Virus
A nonliving infectious agent, a bag of DNA or RNA surrounded by a protein, that needs a host to reproduce.
Obligate Parasite
Obligate Parasite
An organism that cannot live outside of a living host.
Filterable Virus
Filterable Virus
A virus that is smaller than bacteria, and can pass through filters designed to trap bacteria.
Emerging Virus
Emerging Virus
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Envelope Virus
Envelope Virus
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Antibiotics
Antibiotics
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Secondary Infections
Secondary Infections
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Smallpox
Smallpox
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Non-envelope virus
Non-envelope virus
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Viral Replication Stages
Viral Replication Stages
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Lytic Cycle
Lytic Cycle
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Lysogenic Cycle
Lysogenic Cycle
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Reverse Transcriptase
Reverse Transcriptase
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Bacteriophage
Bacteriophage
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ssRNA Virus
ssRNA Virus
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Glycoprotein Spikes
Glycoprotein Spikes
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Retrovirus
Retrovirus
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Antiviral drugs
Antiviral drugs
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Vaccination
Vaccination
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Herd Immunity
Herd Immunity
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Protease
Protease
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Antigens
Antigens
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Memory Cells
Memory Cells
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Innate Immunity
Innate Immunity
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Adaptive Immunity
Adaptive Immunity
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Humoral Immunity
Humoral Immunity
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Cell-Mediated Immunity
Cell-Mediated Immunity
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Natural Killer Cells
Natural Killer Cells
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Study Notes
Filterable Viruses
- Chamberland (1800s) filtered tobacco leaf infected with tobacco mosaic virus, filtering out bacteria, then rubbed filtered paste onto uninfected leaf causing disease.
- This proved viruses exist and are smaller than bacteria.
Infectious Fluids & Infectious Agents
- Cell-free filtered infectious fluids remained infectious, proving infectious agents are smaller than bacteria.
- Common cold caused by rhinovirus.
- Emerging viruses appear suddenly, e.g., COVID, avian influenza (H5N1).
- Virus is a bag of DNA or RNA surrounded by a protein capsid.
- Nonliving infectious agents are obligate parasites needing a host and are generally too small to filter out. Antibiotics do not kill viruses.
- Secondary bacterial infections occur sometimes and can be prevented using antibiotics, e.g., bacterial pneumonia and whooping cough.
Viruses: Random Facts
- Measles: rash, respiratory infection
- Mumps: lymph nodes, can cause sterility in males
- Polio: spread via fecal contamination, waterborne, March of Dimes funded polio research (1930s-1950s)
- Rabies: has a vaccine for dogs
- Shingles: a herpes virus, chicken pox
- Warts: treated by freezing/burning to trigger immune system, liquid nitrogen
- HPV: can cause warts and certain cancers (cervical, penile)
- Colorful tulips can be infected with a virus
- Smallpox globally eradicated (1970s) via vaccine
- Smallpox vaccine causes pustules full of live virus, potentially contagious when ruptured.
- Canker sores/cold sores: herpes 1 virus.
Virus Types
- Envelope virus: virus with a phospholipid envelope (e.g., influenza).
- Non-enveloped/Naked virus: lacks an outer envelope (e.g., herpes).
Virus Structure & Replication
- Electron microscope needed to view viruses.
- Yellow fever transmission: monkeys -> mosquitos -> humans (South America, 1901).
- Controlling viruses via vaccination or chemical control.
- Bacteriophage: viruses that infect bacteria are complex viruses.
- Types of nucleic acids found in viruses: ssRNA, ssDNA, dsDNA, dsRNA.
- Examples of viruses: Parvovirus (ssDNA), influenza (ssRNA)
- HIV attacks T-helper cells, leading to loss of immune function.
- Retroviruses (HIV): reverse transcriptase transcribes RNA to DNA.
- Viral replication: capsids assemble around new genomes to form new viruses.
- Glycoprotein spikes help some viruses attach to host cells.
Viral Infection Cycle
- Viral Lysis is the destruction of a host cell by a virus through replicated viruses.
- The lysogenic cycle is a viral reproductive cycle in which the viral DNA is added to the host's DNA and is copied along with the host's DNA.
- Virus binding to a host cell receptor(s) is called absorption.
- Viral DNA gets released inside the host cell's cytoplasm, called penetration and uncoating.
- Viral DNA is replicated using host machinery and produces new nucleic acids.
- New viruses are assembled and released.
Antiviral Drugs
- Inhibition of viral entry (e.g., Amantadine for HIV, Tamiflu for influenza).
- Inhibition of nucleic acid synthesis (e.g., Acyclovir for herpes, AZT/Zidovudine for HIV).
- Inhibition of viral assembly/release (e.g., Saquinavir for HIV).
- Examples of antiviral drugs: Amantadine, Tamiflu, Acyclovir, AZT/Zidovudine, Nevirapine, Saquinavir
Vaccine Requirements for Effective Vaccines
- Low level of adverse side effects, no serious harm/toxicity.
- Protection against exposure to wild, natural, and artificial forms of pathogen. Protection of those who can not be vaccinated.
Toxoid Vaccine
- Toxoid vaccines use inactive toxins to stimulate an immune response (e.g., tetanus).
Vaccine Types
- Attenuated vaccines use weakened but living pathogens (e.g., smallpox).
- Inactivated vaccines use killed or inactivated pathogens (e.g., flu vaccines).
- Subunit vaccines use specific antigenic proteins of pathogens (e.g., whooping cough vaccines).
- Acellular vaccines use parts of bacteria to elicit an immune response (e.g., tetanus).
Microbe Parts Vaccines
- Parts of microbes (i.e., antigens of viruses or bacteria) are used to stimulate immunity without pathogens.
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Description
This quiz explores the fascinating world of viruses, from their discovery in the 1800s to their characteristics as obligate parasites. Learn about different types of viruses, their effects on humans, and the role of antibiotics in treating secondary infections. Test your knowledge on key concepts related to infectious agents and viral diseases.
