virus as pathogens Flashcards
bacteriophages
viruses that attack and destroy bacteria
whats the main way viruses cause symptoms of disease
when they cause the lysis of host cells
protein coat of viruses
some viruses have protein coat
-act as toxin causing disease
what happens when viruses take over the metabolism
some viruses cause the host cell itself to make toxins
feature of viral infections
they are often specific to particular tissues
adenoviruses as example of viral infections being tissue specific
-cause colds that affect tissues of gas exchange system but dont affect cells of brain or intestine
result of specificity of viral infections
results in presence or absence of antigenic markers on surface of host cells
features of markers on virus cells
each type of cell has its own markers and each type of virus can only bind to particular antigens on the host cells
effect of presence or absence of antigens in viruses
presence or absence of antigens can effect vulnerability of whole groups of living organisms to attach by viruses
angiosperms example
angiosperms - true flowering plants
-commonly affected by viruses but gymnosperms- confiers and their relatives - almost free of viral diseases
whats influenza
flu
-common respiratory disease
-highly infectious
-has short incubation period
what does influenza virus do
it mutates frequently so it can overcome immune response of the body
epidemics
higher than average number of people are infected with disease in particular area or country
pandemics
higher than average number of people are infected with disease across number of countries
three major strains of influenza
Influenza A B and C
