Biological agents as causes of diseases 0.0 / 5 ? BiologydiseaseUniversityNone Created by: ppogbaCreated on: 22-08-19 16:22 What are the 3 categories of pathogen? Obligate, Facultative, Opportunistic 1 of 16 What are Obligate pathogens? can only survive in host usually very specific to host species 2 of 16 What are Facultative pathogens? present in the environment (reservoir) waiting for host. 3 of 16 What are Opportunistic pathogens? normally benign but cause disease in compromised host. 4 of 16 What do bacteria cause? cholera, typhoid, food poisoning and syphilis. 5 of 16 What do Eukaryotes cause? malaria, thrush, athletes foot 6 of 16 What do Viruses cause? AIDS, small pox, common cold. 7 of 16 What are virulence genes? 2 closely related species can be pathogenic and harmless often differing by only a few genes. (they are key to creating pathogenic species). 8 of 16 What are bacteriophages? bacterial viruses (virulence genes can be carried on them, which incorporate into bacterial DNA. 9 of 16 There are hundreds of strains of Vibrio cholerae, but only some are virulent. Why? only some of the strains are infected with a certain bacteriophage. Bacteriophage transfers the genes that encode cholera toxin to the bacteria. 10 of 16 How does the cholera toxin cause diarrhoea? dehydrating the cells of the intestine, spreading the infected bacteria to new hosts. 11 of 16 Fungal pathogens often show dimorphism. Explain? they grow as cold at low temps. in soil, bu then switch to yeast when inhaled into warm lungs, where in the yeast form it is engulfed by macrophages. 12 of 16 Why can anti-fungal treatments be less effective than anti-biotics? due to their eukaryote nature and dimorphism. 13 of 16 What do you call an insect that transmits a disease? a vector 14 of 16 Bacterial pathogens can invade non-phagocytic cells. What are the 2 mechanisms called that allow them to do this? (What diseases come from each?) Zipper mechanism (listeriosis, bubonic plague), trigger mechanism (typhoid fever, dysentery). 15 of 16 What do these mechanisms both cause? actin-polymerisation, the active rearrangement of the cell. 16 of 16
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