Microbes: Invisible Invaders ... Amazing Allies GLOSSARY

antibiotic: A medicine that kills bacteria or stops their growth. Some are made by humans, others are made by other microbes.

antibodies: Special microbe-fighting proteins in your blood. By attaching to invading microbes, they help white blood cells spot invaders and 'eat' them up.

bacteriophage: A virus that infects bacteria.

cilium: A hairlike structure on some cells. It beats rapidly to move the cell or produce feeding currents. (plural: cilia)

contagious disease: A disease capable of being transmitted from one person to another.

DNA: A molecule shaped like a twisted ladder that carries genetic information in the (deoxyribonucleic acid) nucleus of a cell.

electron microscope: A microscope that bounces atom particles (electrons) off objects to create an image on film.

epidemic: The rapid spreading of an infectious disease to many individuals in an area.

flagellum: A whiplike structure on some cells that helps them swim. (plural: flagella)

fungus: A complex microorganism that absorbs nutrients from either living organisms or the remains of dead organisms. Fungi include molds, mildew, yeasts, mushrooms and others that cause severe human illness. (plural: fungi)

gene: A piece of DNA that determines a specific trait in an organism.

genetic engineering: The artificial altering of a living organism's genetic material to produce new traits, species or products.

germ: A microbe, usually one that causes disease.

immune: Having the ability to resist a specific disease.

infection: Invasion and multiplication of microbes in body tissues.

infectious disease: A disease caused by an infectious agent; contagious disease.

inoculation: The introduction of disease-causing microbes into the body to produce or boost immunity to a specific disease.

light microscope: A microscope that uses light to make a specimen visible.

microbe: An organism so small you can see it only with a microscope; a minute living organism.

microbiology: The study of microbes.

microorganism: A microbe.

mildew: 1) Any fungus that attacks plants, paper, cloth and other objects, and forms a downy or powdery whitish growth; 2) The whitish growth formed by some fungi.

mold: 1) Any fungus that feeds on live, dead or decaying matter, and forms a slimy, cottony growth; 2) The slimy, cottony growth formed by some fungi.

molecule: A combination of atoms of a specific substance forming the smallest unit that can exist alone.

pandemic: An epidemic that has spread over a large geographic area, throughout an entire country, continent or the whole world.

parasite: An organism that grows and feeds on or within another organism (host), but offers no benefits to the host.

phage: A bacteriophage.

plague: An infectious and usually deadly epidemic disease.

strain: A group of organisms of the same species that are more like one another than others in the species.

vaccine: A preparation of killed or weakened microbes (or portions of them) that when taken into the body, causes the immune system to produce antibodies and makes the body resistant to the disease.

X-ray crystallography: A method of seeing viruses by turning them into crystals, shooting them with X-rays, then recording the image on film.

yeast: Any of a number of one-celled fungi that break down sugar into alcohol and carbon dioxide.