Protozoa

protective capsule called cyst

cyst allows parasitic species to live outside of hose

oocyst: phylum Apicomplexa--cells produce asexually

asexually by fission, budding or schiogony

schizogony: multiple fission, nucleus undergoes division before cell divides--cyto surrounds the many nuclei then separates

sexual by conjugation: two cells fuse and haploid nucleus from each cell migrate to the other cell. Haploid micronuclei fuse and parent cells separate each now a fertilized cell

some form gametes

unicellular

eukaryotic

chemoheterotrophs

water and soil

trophozite: feeing and growing stage--feed upon bacteria and small particles

normal microbiota of animals

few cause human disease

malaria 4th leading cause of death

Archaezoa

eukaryotes that lack mitochondria

mitosomes instead

symbiontsi n animals

spindle-shaped with front end flagella

Subtopic

Trichomonas vaginalis: human parasite

undulating membrane: membrane bordered by flagellum

Giardia lamblia: small intestine--excreted in feces as cysts--giardiasis

Microspora

eukaryotes that lack mitochondria

no microtubules

obligate intercellular parasites

Amoebozoa

move by extending pseudopods

Entamoeba histolytica: only path. amoeba in humans

lectins attach to galactose on PM and cause cell lysis

E. dispar: nonpath in human and is most common

Acanthamoeba: in water can cause blindness

Balamuthia: brain abcesses

Apicomplexa

nonmotile in mature form

obligate intracellular parasites

complex of special organelles at tip that penetrate host

Plasmodium: malaria

sexual reproduction in Anopheles mosquito

1. sporozite (infect stage) injected into human and carried to liver

2. undergo schizogony in liver cells and produce progeny called merozoites

3. merozoites enter bloodstream and infect red blood cells

4. young trophozoite look like a ring in which the nucleus and cyto are visible--ring stage

5. ring stage enlarges and divides repeatedly

6. red blood cells rupture and release merozites...waste products that cause fever are released

7. picked up by bite of another mosquito---enter mos. intestine and begin sexual cycle

male and female gametocytes join to form zygote--oocyte formed--divides into asexual sporozoites

8. oocytes rupture and send sporozoites to mosquitos saliva---then they bite a human

mosquito--definitive host--where sexual stage occurs

human--intermediate host--where asexual stage occurs

Babesia microti

red blood cell parasite

fever and anemia in immunosuppressed

transmitted by tick

Tocoplasma gondii

human parasite from domestic cats

trophozoites--called tachyzoites repro sexually and asexually in cat--oocytes w/sporozoites excreted

congenital defects in uetero

Chryptosporidium

human parasite

respiratory and gall bladder infections

Ciliophora

ciliates--cilia arranged in precise rows

Balantidium

human parasite (only ciliated one)

causes severe dysentry

cysts are ingested by host and enter large intestine

Alveolata

ciliates, apicomplexans, and dinoflagellates may be placed here

they all have membrane-bound cavities under the cell surface

same rRna sequences

not sure why this info goes here...

Euglenozoa

Euglenoids

photoautotrophs

pellicle

move by flagellum at anterior end

red eye spot to sense light

some are facultative chemoheterotrophs

can photosynthesize

hemoflagellates

blood parasites

long slender bodies with undulating membrane

Trypansoma: African Sleeping sickness

T. brucei gambiense: tsetse fly transmission

T. cruzi: Chagas' Disease--"kissing bug" b/c is bites on face

mostly aerobic heterotrophs

in intestines anaerobic growth

need lots of water

pellicle--special covering

ciliates wave food to special opening called cytosome

amoebas phagocytize and digestion is in vacoules--waste out thru anal pore or PM