bio chapter 20

true or false: like bacteria, a single type of virus can infect many different types of organisms

false

true or false; once inoculated with an influenza vaccine, an individual is immune to that strain of virus for life

false

bacteria use _____ to attach to surfaces or other cells

fimbriae

which bacterial structure is used for locomotion?

flagellum

what does a virus direct a host cell to duplicate?

genetic material

characteristics of a virus

-consists of either DNA or RNA -surrounded by a protein coat -do not have a metabolism -do not respond to stimuli -can replicate only by using metabolic machinery of a host cell

an organism that is unable to grow in the absence of oxygen is a(n):

obligate anaerobe

infectious particle consisting of protein only and no nucleic acid (usually associated with mad cow disease)

prion

organisms that lack a membrane-bounded nucleus and membranous organelles typical of eukaryotes

prokaryotes

an infectious strand of RNA devoid of capsid and much smaller than a virus:

viroid

list the following from smallest to largest. Begin with the smallest at the top of the list. virus, viroid, eukaryote, prokaryote

viroid, virus, prokaryote, eukaryote

an obligate intracellular parasite that can only replicate using a host cell: ______

virus

what portion of an animal virus binds to the host cell membrane?

virus spikes

who was the first person to suggest the existence of a virus , suspecting that it was the cause of rabies?

Louis Pasteur

virus

Noncellular parasitic agent consisting of an outer capsid and an inner core of nucleic acid

during the biosynthesis stage of a retrovirus replication cycle, viral ___ is used to produce viral _____

RNA; DNA

bird flu, zika and west nile encephalitis are all examples of _____ viral diseases

emerging

how can animal viruses enter a host cell?

endocytosis

what is plasmid?

extra rings of DNA that usually carry accessory genes

viruses are ____ specific because each can only infect one type of living cell

host

the viral enzyme found in retroviruses that is capable of converting their RNA genome into a DNA copy is called _____

reverse transcriptase

a bacterium that functions as a decomposer to break down organic matter of dead organisms is called a(n) _______

saprotroph

mutualism, commensalism, and parasitism are all examples of _____ relationships

symbiotic

the disease that results from bacterial infection that involves sustained muscle contraction without relaxation is called ______

tetanus

true or false; viruses are not considered to be a living organism

true

mad cow disease and kuru are examples of _______diseases because they destroy nerve tissue in the brain

neurodegenerative

a cytoplasmic region of prokaryotic cells where chromosomal DNA is located

nucleoid

viruses are known as ______

obligate intracellular parasites

how are viruses classified?

only lower taxonomic levels are used for virus classification including genus and species

on average, the size of a virus is about _____

10-400 nm

the retrovirus responsible for causing AIDS is

HIV

a lichen results from a symbiotic relationship between cyanobacteria and what?

a fungus

halophiles, methanogens, and thermoacidophiles are the three main groups of _______

archaea

order the steps of viral reproduction beginning with the first step at the top; attachment, biosynthesis, maturation, release, penetration, integration

attachment, penetration, integration, biosynthesis, maturation, release

a virus that infects only bacterial cells is called a(n)

bacteriophage

the reproductive mechanism which is utilized by most prokaryotes:

binary fission

a dramatic increase in cyanobacterial numbers in a lake as a result of human pollution is called a cyanobacterial ______

bloom

the protective protein coat surrounding the genetic material of a virus:

capsid

which of the following are found in all viruses? envelope, capsid, nucleic acid core, proteins

capsid, proteins, nucleic acid core

which structure of a prokaryotic cell prevents the cell from bursting or collapsing due to fluid pressure changes?

cell wall

bacteria that obtain their carbon and energy by consuming organic nutrients produced by other living organisms are called _______

chemoheterotrophs

a virus is similar in size to a(n)

large protein

the viral reproductive cycle in which viral DNA is incorporated into the host's genome is called the _____ cycle

lysogenic

the viral reproductive cycle that terminates with the destruction of the host cell through cell lysis is called the ______ cycle

lytic