Pathogens Flashcards
All 6 cards in this deck
What is a pathogen?
An organism that causes disease.
What are the four types of organism that can be pathogens?
Viruses, bacteria, fungi and protists.
What are the steps of the lytic pathway of a virus lifecycle?
e.g. a virus infecting a bacterial cell- The virus attaches to the host cell and injects its genetic material.
- The host cell's machinery copies the viral genetic material and makes new viruses.
- The cell lyses (bursts), releasing the new viruses to infect other cells.
What are the steps of the lysogenic pathway of a virus lifecycle?
e.g. a virus infecting a bacterial cell- The virus injects its genetic material into the host cell.
- The genetic material joins the host DNA as a provirus and is copied each time the cell divides; no new viruses are made.
- A trigger activates the provirus, which leaves the host DNA and enters the lytic pathway.
True or false? In the lysogenic pathway the host cell is destroyed straight away.
False. The viral genetic material lies dormant as a provirus in the host DNA; the cell is only destroyed once the virus switches to the lytic pathway.
True or false? Chalara ash dieback is caused by a fungus.
True. Its airborne spores infect ash trees, causing leaf loss and bark lesions.