HLTB21H3 Lecture Notes - Tuberculosis, Rodent, Herd Immunity
Document Summary
Parasites: organism that grows, feeds, and is sheltered on or in a different organism and that does not contribute to the survival of its host. Organism that is not able to survive on it"s own so it needs a host for nourishment. In the process of doing so it causes harm to it"s host. Virus: ultimate micro-parasite smaller than bacteria; neither cells not organisms; can only reproduce within their host. Fragments of genetic material wrapped inside a protein: need a microscope higher than 10,000x to be seen, lives only inside the body (ex. Hiv infects the host and eventually may become aids, measles) Macro-parasites: composed of many cells; cycles through transmission stages (eggs and larvae) which pass into the external environment. They do not necessarily multiply within the host, they do this in the outside environment but they need the host to perform their transmission stages. Can be seen using the naked eye.
