Micro exam 2 eukaryotes: protozoa

protozoa characteristics

first or tiny animals, no cell wall, unicellular eukaryotes, must move around*

how do protozoa move around?

flagella, cilia, or pseudopodia

where can protozoa be found?

very moist environments, critical members of plankton

encystment

the production of a protective capsule (cyst) by a protozoa

what do cysts allow?

survival in unfavorable conditiosn: lack of food, moisture or oxygen, bad temperatures, toxic chemicals; allow survival of parasitic species outside of host cell

can protozoa have chloroplasts?

yes

how do protozoa get nutrients?

phagocytosis; bacteria, decaying organic matter, other protozoa, host tissues; can absorb surrounding water; dinoflagellates and euglenoids are photoautotrophic

what is a pellicle?

a protective covering that requires certain structures to bring food into the protozoa

what do ciliates do?

wave cilia toward a mouth-like opening called the cytosome

where does protozoa digestion take place?

in a vacuole

dinoflagellates

most are photosynthetic, can produce their own bioluminescence, can cause red tides

pfiesteria piscicida

carnivorous dinoflagellate; produce toxin that can stun fish, can cause headaches, skin irritation, weight and memory loss

ciliates

ciliophora; a diverse protist group that use cilia to move and feed

balatidium coli

only human parasite, causes rare and severe dysentery; also known as paramecium

paramecium

expel water from the cell into the surrounding area, oral groove that food is engulfed by phagocytosis

apicomplexa

obligate intracellular parasites, specialized organelles at apexes, penetrate host tissue, can be transmitted through many hosts, hard to make a vaccine

toxoplasma gondii

cat to human disease

cryptosporidium

passed through fecal contamination, has outer shell protection, can survive outside of body for long time, can survive days in swimming pools

cyclospora cayetanensis

cases of diarrhea associated with raspberries

toxoplasmosis

Common diseases found in birds and mammals, cysts are shed in feces and reach humans

What percentage of the population is estimated to be infected with Toxoplasma?

30-60

plasmodium vivax

MALARIA, the definitive host is a mosquito (harbors sexually reproducing stage), the intermediate host is a human (harbors asexually reproducing stage) and the infective stage is a sporozite

schizogony

unique to protozoa; has multiple mitoses. the nucleus divides via mitosis and then the cell divides when multiple nuclei are present

how do sporozoites form?

gametocytes → zygotes → sporozoites

how are merozoites formed?

sporozoites undergo schizogony in the liver to form merozoites

what type of reproduction is the ring stage in RBCs?

asexual reproduction

diplomonads

multiple flagella, 2 separate nuclei, no mitochondria or plastids, example is giardia lamblia

giardia lamblia

a parasite that infects the human intestine: giardiasis

parabasalids

trichomonas vaginalis (inhabits the vagina STD)

amoebas

lack mitochondria, inhabit freshwater and marine, use pseudopods for movement

pseudopodia

cellular extensions to move and feed

which group of protozoa is unlikely to cause disease in humans?

ciliophorans

entamoeba histolytica

causes amoeboid dysentery in humans

acanthamoeba

infection of cornea, blindness, transmitted through water

balamuthia

amoebic (cause brain or spinal swelling) transmitted via water

foraminifera

shelled amoeba, less than 1mm in size

euglenoids

photoautotrophs, photosynthetic, some are facultative chemoheterotrophs, pellicle, flagellum, red eyespot

kinetoplastida

single large mitochondria, symbiotic and include pathogenic parasites

kinetoplast

houses extranuclear DNA

hemoflagellates

blood parasites, transmitted via insect feces

what is african sleeping sickness caused by?

tsetse fly

what is chaga’s disease caused by?

kissing bug

what disease that is protozoan kills the most humans annually?

malaria