General Characteristics and Life Cycles of Viruses

Vocabulary flashcards covering the basic structure, morphology, classification, and replication cycles of viruses based on introductory biology notes.

Obligate intracellular parasite

An entity, such as a virus, that cannot replicate or carry out metabolic processes on its own and must rely entirely on a target host cell.

Capsid

The protective protein coat or shell that surrounds and encloses the nucleic acid of a virus.

Virion

The complete, structurally intact, and inactive extracellular form of a viral particle outside of a host cell.

Viral genome

The genetic material of a virus, consisting of either DNA or RNA, organized as a single strand or a double strand.

Pericapsid (Envelope)

An outer phospholipid bilayer membrane that surrounds the protein capsid in certain types of viruses.

Helical structure

A viral morphology characterized by a cylindrical, spiral arrangement of capsomers around the nucleic acid.

Polyhedral (Icosahedral) structure

A geometric viral capsid shape composed of flat triangular facets, typically forming a 20-sided regular icosahedron.

Bacteriophage

A virus exhibiting a complex morphology that specifically targets, infects, and replicates within bacterial cells.

Lytic cycle

A viral reproductive cycle in which the virus hijacks host cell machinery to produce viral nucleic acids and proteins, culminating in cell lysis and release of new virions.

Lysogenic cycle

A viral reproductive cycle in which viral DNA integrates into the host cell's chromosome, replicating passively alongside host cellular division without causing immediate lysis.