Excess mucus and secretions in the air passages of the nose.

Lymph nodes in the neck that are small, bean-shaped organs that help the body recognize and fight germs, infections, and other foreign substances.

Lymph nodes located in the back of the throat.

High-pitched whistling sound during breathing. It occurs when air moves through narrowed breathing tubes in the lungs.

Select all that apply:

You can see them with a regular classroom microscope.

Select all that apply:

They need a host to multiply.

Select all that apply:

They can mutate, making them difficult to prevent or treat.

Select all that apply:

They can be passed from person to person.

Select all that apply:

There are good and bad versions.

Select all that apply:

They like moist warm environments to reproduce.

Tiny infectious agents that can only multiply when they are inside a host, the living cells of plants, animals, or bacteria.

Single-celled organisms that do not rely on a host.

Organisms such as yeasts or molds that reproduce quickly in moist, humid environments.

A microscopic organism such as a bacterium, virus, or fungus.

A medicine that limits the growth of or destroys microorganisms.  

The time between contact and onset of illness.