Transmission
What is the main way viruses spread from person to person?
Through contact, droplets, or bodily fluids.
In which viral cycle does the host cell burst open to release new viruses?
The lytic cycle
Obligate intracellular pathogens that invade cells in order to replicate.
Virus
What is one major public health tool used to prevent HPV infections?
The HPV Vaccine
Why are viruses not considered living organisms?
Viruses are unable to reproduce independently.
Why is indoor transmission of viruses often higher than outdoor transmission?
Enclosed spaces increase the chances of interaction and exposure to infected material.
What happens to the viral DNA during the lysogenic cycle?
It integrates into the host’s DNA and remains dormant for a period.
The protein shell of the virus.
Capsid
What body system does rabies primarily affects?
The Nervous System
Some viruses only infect bacterial cells, what are these types of viruses called?
Bacteriophages
How do viruses attach a host cell?
specific viral proteins on their surface to bind to corresponding receptors on the host cell membrane
What is the role of the host cell’s ribosomes during viral infection?
They make viral proteins using viral RNA instructions.
What types of genetic material can viruses contain, RNA or DNA?
Both!
Why do humans need a new flu shot nearly every year?
Influenza A mutates rapidly, changing its surface proteins so older antibodies no longer recognize it.
What do Epidemiologists do?
They are scientists who study how illnesses spread, who they affect, and how to stop outbreaks.
Why might a virus that causes mild symptoms spread more effectively than one that kills hosts quickly?
Hosts remain active and interact with others, increasing transmission opportunities.
What can trigger a lysogenic virus to enter the lytic cycle?
Environmental stress or host cell damage.
Viral proteins on the capsid will attach to these proteins on the cell membrane.
Host Cell Receptor
How does HIV weaken the immune system over time?
It infects and destroys helper T cells (CD4 cells), reducing immune defense.
What is the difference between a vaccine and an antiviral drug?
a vaccine is preventative fight a virus before infection, while an antiviral drug is a treatment used to control and reduce symptoms after an infection has occurred
Some viruses can infect multiple species, while others infect only one. What factors determine this host range?
Specificity of viral surface proteins to host cell receptors and host cell machinery compatibility.
DNA replication has a significant amount more checkpoints than transciption during its process to ensure integrity of the genetic material. Why might this be advantageous for an RNA based virus?
Lack of proofreading allows for viruses to evade immune response, or adapt/mutate rapidly to better survive.
Viruses use these to convert genetic material into proteins to construct new viruses.
Ribosomes
What made Coronavirus (SARS-CoV-2) different from other coronaviruses discovered before 2019?
It was a new strain capable of human-to-human airborne transmission, leading to the COVID-19 pandemic.
Ciprofloxacin is known as a “quinolones", or an antibiotic that inhibits cell replication in bacteria. Why would a treatment of Ciprofloxacin be ineffective in treating a human suffering from a viral syndrome?
What is, viruses lack the mechanisms targeted by the antibiotic, meaning they are unaffected by it’s treatment.