Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers



  1. What is the life cycle of the
    schistosome?


Male and female adult schistosomes live


within intestines.blood vessels of the human The females release eggs (^)
that trespass the vessel walls and enter
the intestinalwith the human feces. Wh lumen being eliminateen in watedr (^)
the egg releases a larva called
miracidium snail that is ththat then swimse intermediate to reach thehost.
Within the snail miracidia transform into
cercariae, larva. The cercariae lanother kind of schistosomeeave the snail and (^)
swim until penetrating through the
human skin. Ingains the circulation humans t infecting mainly the cercaria (^) he
blood vessels of the intestines, liver or
lungs and develops into thof the parasite. e adult form



  1. What are the main phases
    and clinical manifestations of
    schistosomiasis?


Schistosomiasisphases. Days after the infection th has acute and chronice


cercarial dwhere the worm ermatitispenetrate appears at thd the skin. Ie site (^) n
one or two months the acute phase
begins and fever, cough, muscle painand nausea occur but soon disappear; in (^)
some people this phase may not
manifest. Indisease the worm the chronic phinfestationase of the can affect (^)
the bowels, causing diarrhea, bloody
feces, tirehepatosplendness andomegaly (enlargem (^) ent of
the liver pressure upon the hepatic portal vand spleen). The excessiveein (^)
produces varix (collateral circulation) in
the esophagus and the patient may
have hemorrhages and bloody vomiting
that may even cause death.



  1. What are the main
    prophylactic measures against
    schistosomiasis?
    The main measures to prevent
    schistosomiasisinfected individuals to lo are: information ok for for
    treatment and to not disseminate the
    disease; chagainst the vector snail; basicemical and biological combat sanitary


conditions to avoilakes, rivers and other water d contamination streamsof (^) by
infected feces; to avoid contact with
fresh water suspected of contamination.



  1. What are taenias? What are
    the diseases caused by them?


Taenias, also knplatyhelminth animalsow as tapew (flatworms).orms, are The (^)
main diseases caused by taenias are
taeniasis and cysticercosis.



  1. How do taenias classify
    according to the division of
    sexes?
    Taenias are monoecious
    (hermaphrodite), thhas female and male e same reproductiveindividual
    organs and undergoes self fecundation.


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