Virus
* Viruses are not considered organisms because they are not living
and not made of cells
* Viruses are DNA or RNA surrounded by a protein coat
* Viruses are pathogens- disease causing agents
Examples: influenza, HIV
Virus
* Viruses can only reproduce by inserting their DNA into a host cell
Two Methods of Replication
1. Lytic Cycle: Immediate replication with host cell
death
- Cell reproduces virus DNA/RNA and proteins
- Cell bursts and new viruses are released
Virus
* Viruses can only reproduce by inserting their DNA into a host cell
2. Lysogenic Cycle: Period of
inactivity
- Virus DNA gets incorporated into
host DNA
- Virus DNA gets replicated
indefinitely until lytic cycle begins
Virus
* Lytic and Lysogenic Cycles of Replication
Virus
Viral infections can not be cured!
* Medications, like antivirals, can help with the symptoms
of a viral infection
* Antibiotics will not help a viral infection
* Vaccinations may lessen your chance of acquiring a
viral infection
Virus
Viral infections can not be cured!
Influenza
* Influenza infects cells of the respiratory tract
Influenza Transmission
* Influenza is airborne
Virus
Human Immunodeficiency Virus
* HIV infects human immune cells (white blood
cells)
* Weakens the immune system making a person
susceptible to disease that a healthy immune system
could fight off
Virus
Human Immunodeficiency Virus
* When your immune system is weakened a
person is diagnosed with AIDS, Acquired
Immune Deficiency Syndrome
HIV Transmission
* blood
* semen
* vaginal fluids
* breast milk