BIO SCI E109 Lecture Notes - Lecture 2: Ecotone, Naegleria, Night Soil
1 Oct 2016
School
Department
Course
Professor
Document Summary
[1] oral/fecal cycles: encysted protozoan (toxoplasma , giardia ) or helminth (tapeworms) eggs can persist in the environment after being shed in feces. These are accidentally ingested in contaminated food or water to initiate infection. [2] hematophagous insects : blood sucking insects are both hosts for and vectors of protozoan (malaria, sleeping sickness) and helminth (filarial worms) parasites. [3] other: inhalation of naegleria from fresh water, sexual transmission of trichomonas. Hookworms and schistosomes directly invade into skin. Parasitic infections are mostly preventable with access to: screens/bed nets/insecticides (vector borne) safe food/water/sewerage disposal (water & foodborne: parasite transmission depend upon complex elements. [2] altered ecosystems fecal-oral contamination of environment: contaminate water&food use of night soil as fertilizer: human behaviors fragmentation of ecosystems ecotones created diversity of life is higher. Ecotone: a transitional zone between two adjacent ecological communities containing the characteristic species of each & exhibiting competition between these shared organisms. human modification of the environment between zones.
