Chapter 11 Flashcards
Obligate parasite
they must spend at least some of their life cycle in or on a host (protazoan that causes malaira)
Faculative parasites
normally free living (fungi)
Accidental parasites
invade an organism other than their host (ticks on human)`
Vectors
agents of transmission (mosquitoes to malaria)
Biological vector
a vector in which the parasite goes through part of its life cycle (Mosquito to malaria)
Mechanical Vector
a vector in which the parasite DOES NOT go through part of its life cycle (flies that carry paraste eggs, bacteria or viruses from feces to human food are mechanical)
Definitive host
Host are classified as definitive hosts if they harbor parasites while it reproduces sexually (mosquito to malaria)
Intermediate host
Host are classified as intermediate hosts if they harbor the parasite during some other developmental stage (human to malaria )
Reservoir host
are infected organisms that make parasites available for transmission to other hosts
Host Specificity
refers to the range of different hosts in which a parasite can mature
4 mechanisms parasites have to evade host defense
- encystment
- changing surface antigens faster than host can make antibodies
- cause the host to make antibodies that cannot reacr with the parasites antigens
- invade host cells, where they are out of reach of host defense mech.
Schizogony
multiple fission, in which one cell gives rise to many cells
Hermaphrodtic
one organism has both male and female repo systems and are both functional
Eutrophication
the process in which autotrophic protists multiply very rapidly in abundent ingoranic nutrients anc form a “bloon” a think layer of organism over a body of water
Euglenoids
(Plantlike protists)
usually have a single flagellum and a pigmented eye spot called a stigma
Pellicle
possed by euglenoid as an outer membranous cover
diatoms
(Plantlike protists)
lack flagella
numerous group and are important as producers in both freshwater and marine environments
Dinoflagellates
(Plantlike protists)
-two flagella
Oomycota
(Water Mold)
causes mildew
Saprophytes
(Slime Mold)
organism that feed on dead or decaying matter
Plasmodial slime molds
form a multinucleate amoeboid mass called plasmodium, which moves slowly and phagocytizes dead matter
Fruiting bodies–>sporangia–>Spores
Cellular slime molds
produce pseudoplasmodia, fruiting bodies and spores
Pseudoplasmodium
slightly motile aggregation of cells.
fruiting bodies–>spores
spores germinate into amoeboid phagocytic cells that divide repeatedly
Commensals
(Animal- like protists)
live in or on other organisms without harming them and few are parasites
Mastigophorans
(Animal- like protists)
have flagella
most live in symbiotic relationships
{Trypanosoma, Leishmania, Giardia and Trichomonas}
Ameboza
(Animal- like protists)
move by means of pseudopodia
feed mainly on other microorganisms, including other protozoa and small algae
{forminiferans and radiolarians}
Dientamoeba fragilis
(Animal- like protists)
has two nuclei
does not form cysts
found in 4% of human pop
Apicomplexans
(sporozoans)
parasitic and immobile
Plasmodium (malaria) life cycle
Sporozoites (salivary glands of the mosquitoes)
Merozoites (after 10 days, they emerge into the blood, invade red blood cells)
Trophozoites (reproduce asexually, producing many more merozoites which are released into the blood by rupture of red blood cells
- some enter sexual reproduction and create gametocytes which are taken up by a mosquito through the blood
Ciliates
protozoans
have cilia over most of their sufaces
TRICHOCYSTS-tentacles that can be used to capture prey or to attach themselves to surfaces
-undergo conjugation
3 types of tissue flukes
FLUKE IS FLATWORM paragonimus westermania (lung fluke) clonorchis sinensis ( liver fluke) fasciola hepatica (liver fluke)
life cycle of the parasitic fluke
Miracidia -free swimming flukes that hatch in water
sporocyts- penetrate a snail or other molluskan host and migrate to the digestive
rediae- divide by mitosis
cercarie- free swimming, which escape from the mollusk into the water which then burrow through exposed skin and penetrat another host (often arthropod) and encyst as metacercaria
Define Scolex
head of the tapeworm
define proglottids
body components of the tapeworm that contain mainly reproductive organs of both sexes
microfilaria
roundworms that parasitize humans as larvae may also require a mosquito host. These worms enter the human body as immature larvae
Arthropod
characterized by joint chitinous exoskeletons, segmented bodies and joint appendages
what are the three subgroups (classes0
of arthropods
arachnids
insects
crustaceans
what causes lyme disease
Borrelia burgdorferi
What is the common tick
Dermacentor andesoni
-causes tick paralysis ect.
What are mites the vector for
regarding ticks
rickettsial disease
scrub typhus
Q fever
What is the main vector for ruckettsia (that causes typhus and trench fevers)
body louse
Accidental parasite
Parasite that invades an organism other than its normal hose
Host specificity
Range of different hosts in which a parasite can mature
Intermediate Host
Harbors a parasite during any part of its developmental stage EXCEPT the sexual reproduction stage
Reservior host
Infected organisms that make parasites available for transmission to other hosts
Definitive host
Host that harbors a parasite while it reproduces sexually
Obligate parasite
Must spend at least some of its life cycle on or in a host
