Key Terms

Sections

Key Terms

Key Terms

acellular: lacking cells

acute disease: disease where the symptoms rise and fall within a short period of time

asymptomatic disease: disease where there are no symptoms and the individual is unaware of being infected unless lab tests are performed

attenuation: weakening of a virus during vaccine development

AZT: anti-HIV drug that inhibits the viral enzyme reverse transcriptase

back mutation: when a live virus vaccine reverts back to it disease-causing phenotype

bacteriophage: virus that infects bacteria

budding: method of exit from the cell used in certain animal viruses, where virions leave the cell individually by capturing a piece of the host plasma membrane

capsid: protein coating of the viral core

capsomere: protein subunit that makes up the capsid

cell necrosis: cell death

chronic infection: describes when the virus persists in the body for a long period of time

cytopathic: causing cell damage

envelope: lipid bilayer that envelopes some viruses

fusion: method of entry by some enveloped viruses, where the viral envelope fuses with the plasma membrane of the host cell

gall: appearance of a plant tumor

gene therapy: treatment of genetic disease by adding genes, using viruses to carry the new genes inside the cell

group I virus: virus with a dsDNA genome

group II virus: virus with a ssDNA genome

group III virus: virus with a dsRNA genome

group IV virus: virus with a ssRNA genome with positive polarity

group V virus: virus with a ssRNA genome with negative polarity

group VI virus: virus with a ssRNA genomes converted into dsDNA by reverse transcriptase

group VII virus: virus with a single-stranded mRNA converted into dsDNA for genome replication

horizontal transmission: transmission of a disease from parent to offspring

hyperplasia: abnormally high cell growth and division

hypoplasia: abnormally low cell growth and division

intermittent symptom: symptom that occurs periodically

latency: virus that remains in the body for a long period of time but only causes intermittent symptoms

lysis: bursting of a cell

lysogenic cycle: type of virus replication in which the viral genome is incorporated into the genome of the host cell

lytic cycle: type of virus replication in which virions are released through lysis, or bursting, of the cell

matrix protein: envelope protein that stabilizes the envelope and often plays a role in the assembly of progeny virions

negative polarity: ssRNA viruses with genomes complementary to their mRNA

oncogenic virus: virus that has the ability to cause cancer

oncolytic virus: virus engineered to specifically infect and kill cancer cells

pathogen: agent with the ability to cause disease

permissive: cell type that is able to support productive replication of a virus

phage therapy: treatment of bacterial diseases using bacteriophages specific to a particular bacterium

positive polarity: ssRNA virus with a genome that contains the same base sequences and codons found in their mRNA

prion: infectious particle that consists of proteins that replicate without DNA or RNA

productive: viral infection that leads to the production of new virions

prophage: phage DNA that is incorporated into the host cell genome

PrP^c: normal prion protein

PrP^sc: infectious form of a prion protein

replicative intermediate: dsRNA intermediate made in the process of copying genomic RNA

retrovirus: virus with an RNA genome that must be reverse transcribed into DNA before being incorporated into the host cell genome

reverse transcriptase: enzyme found in Baltimore groups VI and VII that converts single-stranded RNA into double-stranded DNA

vaccine: weakened solution of virus components, viruses, or other agents that produce an immune response

vertical transmission: transmission of disease between unrelated individuals

viral receptor: glycoprotein used to attach a virus to host cells via molecules on the cell

virion: individual virus particle outside a host cell

viroid: plant pathogen that produces only a single, specific RNA

virus core: contains the virus genome