Chapter 13: Viruses, Viroids, and Prions

________ that infect bacteria are called bacteriophages, or phages.

________ inside living cells by using the synthesizing machinery of the cell.

After being transformed by viruses, many tumor cells contain a virus- specific antigen on their cell surface, called tumor- specific transplantation antigen (________), and transformed cells tend to be irregularly shaped, compared to normal cells.

________ coined the name prion for proteinaceous infectious particles.

Some viroids, called virusoids, are enclosed in a(n) ________.

Each ________ is composed of protein subunits called capsomeres.

The ________ can be demonstrated with a one- step growth curve.

________ are visible against a lawn of bacterial growth on the surface of the agar.

________ were first identified in cancer- causing viruses and were thought to be a part of the normal viral genome.

Some ________ are caused by viroids, short pieces of naked RNA, only 300 to 400 nucleotides long, with no protein coat.

The ________ ends with the lysis and death of the host cell, whereas the host cell remains alive in the lysogenic cycle.

The ________ is then inte- grated into a host cell chromosome as a provirus.

A(n) ________ (or chronic viral infection) occurs gradually over a long period.

________ capable of inducing tumors in animals are called oncogenic viruses, or oncoviruses.

Contain a(n) ________ (sometimes itself enclosed by an envelope of lipids, proteins, and carbohydrates) that surrounds the nucleic acid.

________ were originally distinguished from other infectious agents because they are especially small (filterable) and because they are obligatory intracellular parasites- that is, they absolutely require living host cells in order to multiply.

Require living host cells in order to multiply

spectrum of host cells the virus can infect

Viruses that infect bacteria

The nucleic acid of a virus is protected by a protein coat

Each capsid is composed of protein subunits

consists of some combination of lipids, proteins, and carbohydrates