CHAPTER 13 Flashcards
viruses, viroids, prions are __ disease-causing agents that lack cell structure and cannot metabolize, grow, self reproduce, or respond to their environment.
acellular
tiny infectious agent with nucleic acid surrounded by proteinaceous capsomeres
virus
capsomeres in viruses form a coat called
capsid
a complete viral particle, including a nucleic acid and capsid, outside a cell
virion
it is a virus that infects a bacterial cell
bacteriophage or phage
typically, a virus in a cell proceeds with a __ cycle
lytic replication cycle
what are the 5 stages of the lytic replication cycle
attachment
entry
synthesis
assembly
release
process of removing caspid on virion
uncoating
virions are released from the host cell either by __
lysis of the host cell
extrusion of enveloped virions
it is a process seen only with certain animal viruses
budding
an envelope is derived from a
cell membrane
these phages enter a bacterial cell and remain inactive
temperate / lysogenic phages
temperate phages remain inactive in a process called
lysogeny or lysogenic replication cycle
such inactive phages are called __ and are inserted into the chromosome of the cell and passed to its daughter cells
prophages
results when phages carry genes that alter the phenotype of a bacterium
lysogenic conversion
a prophage may be excised from the chromosome in a process known as
induction
complementary negative sense single stranded RNA is transcribed to serve as a template for more
positive sense single stranded RNA
examples of these are HIV viruses that carry reverse transcriptase, which transcribes DNA from RNA
retroviruses
these viruses carry an RNA dependent RNA transcriptase for transcribing mRNA from the -ssRNA genome
negative sense single stranded RNA
it is a process similar to lysogeny, an animal virus remains inactive in a cell, possibly for years, as part of chromosome or in the cytosol
latency
also known as provirus
latent virus
is uncontrolled cellular reproduction in a multicellular animal
neoplasia
a mass of neoplastic cells ; relatively harmless or invasive
tumor
malignant tumors are also called
cancer
describes the spreading of malignant tumors
metastasis
when a mixture of bacteria and phages is grown on an agar plate, bacteria infected with phages lyse, producing clear areas called
plaques
it is a technique used to estimate phage numbers
plaque assay
are small circular pieces of RNA with no capsid that infect and cause disease in plants
viroids
are infectious protein particles that lack nuclei acids and replicate by inducing similar, normal proteins to misfold into new prions.
prions
inducing similar, normal proteins to misfold into new prions is a process called
templating
