Ch 12 Flashcards
contagious
diseases that are easily transmitted by close contact with an infected organism (all pathogens are contagious)
infectious disease
caused by a pathogen that is communicable (passed on from one to another)
a pathogen is…
the infectious agent that causes the disease
pathogens include: prions, viruses, bacteria, fungi, protists, parasites
incubation period
the time between infection and onset of symptoms
what’s the latent period of infection
where the disease cannot be spread
what are the non-cellular pathogens
viruses and prions
what’s a virus and its components
a non-cellular agent composed of a protein coat & nucleic acid (either DNA or RNA, never both)
how does a virus kill a cell
it injects its nucleic acid into the cell which takes over the host cell and directs it to make copies of the virus then will cause the cell to undergo lysis (burst)
what do host cells make copies of when duplicatin viruses
viral protein coat and nucleic acid
what’s an obligate parasite
one that cannot function outside of the host cell e.g viruses
what are the two phases of viral infection
lysogenic phase
lytic phase
list some examples of viruses
influenza
Ross River virus
viral diseases of honeybees
Australian bat lyssavirus
what’s the dormant phase of viral infection
lysogenic phase where nucleic acid is integrated into the chromosome of their host however remains dormant and avoids detection by immune system
what’s the infectious phase of viral infection
lytic phase where viral DNA directs the host cell machinery to produce viral proteins and viral DNA and the cell undergoes lysis
wha do prions do to organisms
degenerate parts of the nervous system and can cause death
