4.1.1: Organisms that cause disease Flashcards
what is an infectious disease and some examples?
disease caused by a pathogen that passes from infected individuals to uninfected
examples; cholera, HIV/AIDS, malaria and tuberculosis
what is a non-infectious disease and give examples?
long-term diseases not caused by pathogens such as lung cancer, cystic fibrosis etc
what microorganisms are pathogens?
bacteria, viruses, fungi, protocists
what is bacteria?
a range of prokaryotic enzymes, those that are pathogenic do not always infect host cells instead they remain within body cavities
examples of diseases caused by bacteria
tuberculosis in humans and ring rot in plants
how does bacteria cause tuberculosis?
the bacteria infects the lungs causing a chronic cough and bloody mucus
how does bacteria cause ring rot in plants?
bacteria infects the vascular tissue preventing the transport of water, causing plant to wilt and die
the infection spreads to potato tubers producing a black ring of rot
why can’t viruses respire, produce ATP or replicate genetic material?
they do not have a cellular structure
how do viruses infect host cells?
they hijack the host cells machinery to replicate their own genetic material and proteins
how does tobacco mosaic virus infect plants?
it causes a distinct yellowing of the leaves producing a mosaic pattern
how do influenza viruses infect humans?
influenza A,B,C infect cells that line the airways causing high temperature, body aches and fatigue - the flu
why does influenza A cause most cases of the flu?
it has a caspid that surrounds 8 single-stranded molecules of RNA
what are the characteristics of HIV/AIDS?
attack cells in the immune system compromising the immune response
what are protoctists?
unicellular eukaryotes
how is malaria caused?
the parasite is spread by mosquitoes to humans
what are the characteristics of potato blight?
it is transmitted via spores and leaves brown dots on plants which grow and destroys plant
what is a fungal disease in humans?
athletes foot
what is a fungal disease in plants (bananas)
black sigatoka - spreads through leaves of the plant reducing ability to photosynthesise
