1. Chapter 2
2.5 – Cell wars

2. Cell wars
A disease is any condition that is harmful to or interferes with the well-being of an organism

3. The invaders
Many diseases are caused by agents that invade the body and interfere with the normal activities of cells
The invasion is called an infection
Some of the invaders are living things
Ex: bacteria, fungi, or parasitic worms
These invaders either rob cells of their nutrients or produce waste products that poison cells

4. Bacteria
Many bacteria are helpful but some cause disease and harmful effects
Tetanus, strep throat, and pneumonia are a few common diseases
Bacteria are also responsible for spoiling food and contaminating drinking water

5. Fungi Fungi cause several human diseases
Most of these diseases are just annoying
Ex: Athlete’s foot
Very few of them can be deadly

6. protists Malaria is caused by an animal-like protist called Plasmodium
It is transmitted by infected female mosquitoes
Malaria is widespread in tropical countries

8. Viruses Viruses are often grouped with living invaders
However, they are not living because they are not true cells
A virus contains no nucleus, cytoplasm, organelles, or cell membrane
It is a small strand of genetic information covered by a protein coat

10. viruses Viruses are only active once they invade a living cell
They take over the cell and turn it into a factory for making more viruses
Viruses are responsible for many diseases
Ex: colds, cold sores, influenza, and HIV/AIDS

11. viruses