Virus Flashcards
Definition of a virus?
A non-cellular particle made up of genetic material and protein that can invade living cells
In the structure of a virus, what parts are optional
Neck, and Tail
What are viruses composed of
A core of Nucleic Acid
What is the nucleic acid core surrounded by?
A protein coat called capsid, made from capsomere
The Nucleic Core is made up of
Either DNA or RNA
What are the size of viruses
0.2-0.3 µm and the biggest is 200 nm
Where can cells be
Outside or Inside a cell
How can viruses reproduce
Viruses can reproduce when they invade a living cell
Ways to stop virus activity?
UV & X-Rays
How can viruses act as
They can act as a disease agent and a genetic agent
Each type of viruses can infect cells that are only of a limited variety from hosts. What is this called?
Host Range
What are the two types of cycles viruses can go through for reproduction
Lytic and Lysogenic Cycle
What phases are in a Lytic Cycle
Attachment/Adsorption
Injection
Synthesis
Assembly
Lyses/Release
What phases are in a Lysogenic Cycle
Attachment
Injection
Combination
Replication
Synthesis
Assembly
Lyses/Release
What do Vaccines Contain?
Vaccination involves putting a small amount of an inactive form of a pathogen (disease causing micro-organism) into the body.
Vaccines can contain:
- live pathogens treated to make them harmless
- harmless fragments of the pathogen
- toxins produced by pathogens
- dead pathogens
How do Vaccines help protect you?
The antigens in vaccines stimulate your white blood cell to create antibodies. The antibodies destroy the antigens without any risk of you getting the disease.
And so in the future you are ready and immune to infections of the pathogens your memory cell has remembered. This is because your body can respond rapidly and make the correct antibody as if you had already had the disease.
So if the person later becomes infected with the pathogen after getting a vaccine
The required lymphocytes are able to reproduce rapidly and destroy it
For a vaccination program to be successful, it depends on
Herd immunity
If the majority of a population is vaccinated, not only are those people kept safe, but viruses cannot…
Spread between immunized people
The immunised people provide a barrier that stops the infection from spreading to others in the group. If only a few people are vaccinated, this will help them avoid infection, but it will not protect the group.
