Chapter 19 Flashcards
The protein shell that encloses a viral genome. It may be rod-shaped, polyhedral, or more complex in shape.
Capsid
A membrane that cloaks the capsid that in turn encloses a viral genome.
Viral Envelopes
A virus that infects bacteria; also called a phage.
Bacteriophages
The limited range of host cells that each type of virus can infect.
Host Range
A phage that reproduces only by a lytic cycle.
Virulent Phage
An endonuclease (type of enzyme) that recognizes and cute DNA molecules foreign to a bacterium (such as phage genomes). The ______ cuts at specific nucleotide sequences (_____ sites).
Restriction Enzymes
A type of phage reproductive cycle resulting in the release of new phages by lysis (and death) of the host cell.
Lytic Cycle
A phage that is capable of reproducing by either a lytic or lysogenic cycle.
Temperate Phage
A type of phage reproductive cycle in which the viral genome becomes incorporated into the bacterial host chromosome as a prophage and does not kill the host.
Lysogenic Cycle
A phage genome that has been inserted into a specific site on a bacterial chromosome.
Prophage
An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome; an important class of cancer-causing viruses.
Retroviruses
An enzyme encoded by certain viruses (retroviruses) that uses RNA as a template for DNA synthesis.
Reverse Transcriptase
The infectious agent that causes AIDS. ___ is a retrovirus.
HIV (Human Immunodeficiency Virus)
The symptoms and signs present during the late stages of HIV infection, defined by a specified reduction in the number of T cells and the appearance of characteristic secondary infections.
AIDS (Acquired Immunodeficiency Syndrome)
A general outbreak of a disease.
Epidemics
