To view Protozoa - Mind Map Get Adobe Flash player

Protozoa

Encystement

protective capsule called cyst

cyst allows parasitic species to live outside of hose

oocyst: phylum Apicomplexa--cells produce asexually

Life Cycle

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

General info

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.

Medically Important Phlya of Protozoa

Archaezoa. Microspora. Amoebozoa. Apicomplexa. Ciliophora. Euglenozoa. 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. eukaryotes that lack mitochondria. no microtubules. obligate intercellular parasites. move by extending pseudopods. Entamoeba histolytica: only path. amoeba in humans. E. dispar: nonpath in human and is most common. Acanthamoeba: in water can cause blindness. Balamuthia: brain abcesses. nonmotile in mature form. obligate intracellular parasites. complex of special organelles at tip that penetrate host. Plasmodium: malaria. Babesia microti. Tocoplasma gondii. Chryptosporidium. ciliates--cilia arranged in precise rows. Balantidium. Alveolata. Euglenoids. hemoflagellates. lectins attach to galactose on PM and cause cell lysis. 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. red blood cell parasite. fever and anemia in immunosuppressed. transmitted by tick. human parasite from domestic cats. trophozoites--called tachyzoites repro sexually and asexually in cat--oocytes w/sporozoites excreted. congenital defects in uetero. human parasite. respiratory and gall bladder infections. human parasite (only ciliated one). causes severe dysentry. cysts are ingested by host and enter large intestine. 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.... photoautotrophs. pellicle. move by flagellum at anterior end. red eye spot to sense light. some are facultative chemoheterotrophs. can photosynthesize. 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.

Nutrition

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.