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Flashcards in exam 2 Deck (92)
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1

symbiosis

mutualism and commensalism
permanent association of two organisms that can't exist independently

2

mutualism

both organisms benefit

3

commensalism

one organism benefits the other is unharmed

4

facultative parasite

live both a free living and a parasitic existence during their life cycles

5

obligate parasite

completely dependent upon host for existence

6

what do ectoparasites cause?

infestation (flea, lice, etc. OUTside)

7

what do endoparasites cause?

infections (worms, INside)

8

definitive host

host in which the sexual stage of the life cycle occurs

9

intermediate host

host in which the asexual stage of the life cycle occurs

10

reservoir host

animals other than man which harbor human parasites

11

what are the requirements for transmission of a parasitic infection?

source of infection, mode of transmission, the presence of a susceptible host

12

what are the functions of ectoplasm of protozoan?

excretion, movement, obtaining food/phagocytize, protection

13

what are the functions of the endoplasm of protozoan?

reproduction, digestion

14

sarcodina (amoeba)

pseudopods (extension of ectoplasm)

15

ciliate

cilia

16

mastigophora

flagella

17

sporozoa

non-motile

18

what is a trophozoite?

(troph) the actively reproducing motile feeding stage (easily destroyed by unfavorable conditions, and can become a cyst in unfavorable conditions)

19

what is a cyst?

inactive, nonmotile, nonfeeding stage with protective cell wall (infective stage)

20

what is the most important parasitic amoeba?

entamoeba histolytica

21

where does Entamoeba histolytica live?

large intestines (colon)

22

describe the troph form of E. histolytica

exhibits progressive directional movement
contains one nucleus with a central karyosome
even-staining peripheral chromatin
may contain ingested RBC

23

describe the cyst form of E. histolytica

contains up to 4 nuclei and has cigar-shaped chromotoidal bars

24

what makes entamoeba gingivalis different from E. histolytica

gingivalis lives in the mouth and has no cyst stage

25

where does entamoeba coli live?

large intestine (colon)

26

describe the troph form of E. coli

exhibits sluggish random motility
contains one nucleus with an eccentric karyosome
uneven peripheral chromatin
contains ingested bacteria

27

describe the cyst form of E. coli

contains up to 8 nuclei
chromatoid bars (if present)
irregular with splintered cells

28

where does Endolimax nana live?

large intestine

29

how is Endolimax nana recognized?

characteristic nuclear structure (has a large eccentric karyosome "lump of coal") seen in both the troph and cyst stages

cyst: can be ovoid
contains up to 4 nuclei
no chromatoidal bars

30

what does Entamoeba hartmanii look like?

entamoeba histolytica only smaller