1. VIRUSES

2. What are VIRUSES?
1) A nucleic acid (DNA or RNA) surrounded by a coat of protein.
2) Viruses are not considered to be alive (they are not in one of the five kingdoms).

3. Nonliving Properties of Viruses
1) Not made of Cells (no organelles or cell functions).
2) Can’t grow or reproduce on their own (reproduce inside the cells of other organisms).
3) Can be crystallized & stored for years.

4. Examples of Viruses:
Bacteriophage
Capsid
Head
DNA
Tail
Tail Fibers

5. Examples of Viruses:
Influenza Virus
Capsid
RNA
Protein
spikes

6. What is a parasite
An organism that attaches itself and feeds off of another organism.
A parasite does harm to the organism it is attached to
Hookworm
                                      

7. What is a host The organism that is harmed or hurt by the parasite
Example: You are the host to a mosquito

8. Bacteriophage Reproductive Cycle

9. 1- Attach
Virus attaches to cell. Use tail to attach to cell membrane of cell.
Bacteriophage
Bacteria

10. 2- Invade Viral DNA invades cell Virus injects nucleic
acid into the cell.
Viral DNA slides into host cell
Viral DNA penetrates cell membrane/cell wall

11. 3- Copy a) Virus’ nucleic acid attaches to DNA of the cell.
Bacterial DNA
Viral DNA

12. Bacteria is forced to make more & more viruses
3- Copy
b) DNA copies and makes new viruses
Virus takes control of cell & makes new virus particles.
Bacteria is forced to make more & more viruses

13. Cell bursts releasing hundreds of new viruses
4- Release
Cell bursts releasing hundreds of new viruses

14. Bacteriophage Reproductive Cycle

15. Aquired Immune Deficiency Syndrome
5- VIRUSES & DISEASE
HUMANS
a) Colds
b) A.I.D.S.
Aquired Immune Deficiency Syndrome
H.I.V. –
Human Immunodeficiency Virus

16. Deformed Leg Caused by Polio
5- VIRUSES & DISEASE
Iron Lung
HUMANS
Deformed Leg Caused by Polio
c) Polio
F.D.R.

17. 5- VIRUSES & DISEASE
2) ANIMALS
Rabies

18. 5- VIRUSES & DISEASE
3) PLANTS
Tobacco Mosaic Virus

19. How are viruses transmitted?
Direct contact
Touching, body fluids, etc.
Vectors -
mosquitoes, flies, etc
Airborne
Spread by the air

20. Terms to know:
What happens when a disease spreads fast in a certain area?
An epidemic
What system in your body is used to help stop you from getting sick?
The immune system
What is a small amount of a virus injected into your body to give you immunity called?
A vaccine

21. CREDITS