Biology Ch. 18: Viruses and Prokaryotes

Terms	Definitions
virus	An infectious particle made only of a strand of DNA (or RNA) surrounded by a protein coat.
pathogen	Anything that can cause a disease, such as bacteria, fungi, or a virus.
viroids	Infectious particles that cause disease in plants. They are made of single-strand DNA without a protein coat.
caspid	The part of a virus that holds DNA
lytic infection	A type of viral infection in which the host cell bursts, releasing new viral offspring to infect other cells.
infect	To cause disease
lysogenic infection	A type of infection where a virus combines its DNA into the host cell's DNA
host cell	A cell that a virus has attacked and is using to reproduce.
epidemic	A rapid outbreak of an infection. The flu is an example of an __________. In the U.S., 20 million people are infected with the flu every year.
rapid	To happen quickly
vaccine	A substance, often given as a shot, that causes the body to defend against viral diseases. For example, you got the DTAP ________.
flagellum	A long, whip-like structure outside of a cell that is used for movement, kind of like a tail that helps a bacteria swim.
toxin	A poison released by an organism. Bacteria can cause illness because it releases this into the bloodstream.
antibiotic	chemicals that kill or slow the growth of bacteria.