Lesson 2 - Cell Diversity & Viruses Flashcards
What is the virosphere?
The virosphere can be defined as “all those places in which viruses are found or which are affected by viruses.”
True or False: Viruses are not cells.
True: viruses are macromolecular packages that can function and repoduce ONLY within living cells!
What is a name for a virus when it exists outside of a cell as an inanimate particle?
Virons!
What is a capsid?
The capsid is a protein coat which surrounds a nucleic acid.
What is the Baltimore classification of viruses?
This classification system is one of the most popular used for viruses. It categorizes viruses based on type of genome (RNA/DNA) and their method of replication.
What are retroviruses?; explain and give an example.
A retrovirus is an RNA virus which can insert a copy of its genome into the DNA of a host cell. An example is HIV, which causes Acquired Immunodeficiency Syndrome (AIDS).
What are hepadnavirus family viruses?; explain and give an example?
This is commonly known as a Hepatitis B virus and its a DNA type which affects the human liver and causes serious infections.
What are filoviruses?; explain and give an example.
Filovirus encode their genome in the form of single-stranded negative-sense RNA. An example is the Ebola virus which causes hemorrhagic fever.
What are adenoviruses?
Adenoviruses are a group of viruses which cause respiratory illnesses (e.g. bronchitis or pneumonia) or conjunctivitis (an infection in the eye).
What is a bacteriophage?
This is a virus which infects and replicated within bacteria and archaea.
How does a virus attach to a host?
Viruses bind to a cell surface through specific proteins and then enter into the cell.
True or False: “Rabies is a good example of a virus with a narrow host range.”
False: Rabies is a common example of a wide host range, as it infects cells in dogs, foxes, bats, raccoons, and humans!
What is the LYTIC viral life cycle?
The lytic viral life cycle is the production of virus particles which ruptures (and kills) host cell. E.g. bacteriophages.
What is the NON-LYTIC (LYSOGENIC) viral life cycle?
Viral nucleic acid is replicated in the host cell, which produces proteins. Virus reproduces without destroying the host cell.
How does an RNA vaccine work?
RNA vaccines work by tricking the body’s cell into producing a fragment of a virus, an antigen, from an RNA template.
