Chapter 2 - Protozoa Flashcards
What group of protozoans lack mitochondria and Golgi bodies?
Retortamonads
Which group lacks mitochondria but have mitochondrial genes in their cell nucleus?
Diplomonads
Chilomastix and Retortamonas belong to which group?
Retortamonads
What are the two representatives of Retortamonads?
Chilomastix and Retortamonas
How do Giardia infect the digestive tract of humans, birds, and amphibians?
By ingestion of cysts in contaminated water
What do parabasalids possess?
Axostyle, a stiffening rod composed of microtubules
This species causes a sexually transmitted disease in females
Trichomonas vaginalis
A modified region of the Golgi apparatus
Parabasal body
Mutualistic symbionts in termites
Trichonympha, Spirotrichonympha
Another term for Heterolobosea (either of the two)
Ameboflagellates or schizopyrenids
These are naked amebas with eruptive pseudopodia that form abruptly
Heterolobosea
This has amebic stages but can transform to a flagellated stage
Naegleria gruberi
What are the two major subphyla of Euglenozoa?
Euglenida and Kinetoplasta
What do Euglenids have?
Chloroplasts surrounded by a double membrane; chlorophyll b
What do Kinetoplasts have?
Kinetoplasts (a modified mitochondria associated with kinetosome) and large discs of DNA
Euglenid found in freshwater with abundant vegetation
Euglena viridis
How do Euglenia reproduce?
By binary fission; can encyst to survive harsh conditions
Give a representative of Kinetoplasta
Trypanosoma
What is Trypanosoma usually transitted by?
Tsetse fly (Glossina sp.)
Which sub-species of Trypanosoma causes African sleeping sickness? Which is more virulent?
Trypanosoma brucei gambiense and T.b. rhodesiense. T.b. rhodesiense is more virulent
What species of Trypanosoma causes sleeping disease in domestic animals?
Trypanosoma brucei
What causes Chagas disease?
Trypanosoma cruzi
What transmits Trypanosoma cruzi?
Kissing bugs (Triatominae)
Causes skin lesions, mucous membrane disfiguring of nose and throat along with liver and spleen damage
Leishmania sp.
What is Leishmania sp. transmitted by?
Sand flies
These are heterokont flagellates
Stramenopiles
What do the Stramenopiles include?
Brown algae (Phaeophyta), yellow algae (Chrysophyta), diatoms, Opalinids, Labyrinthulids, Oomycetes, Heliozoans
What are Opalinids?
Commensals to frogs
What are Labyrinthulids?
Slime nets; commensal or mutualistic with plants, can be parasitic on eel grass and turf grass
Example of this is the potato blight causing the Irish potato famine (caused by the British btw!!!)
Oomycetes
Testate amoebas with axopodia
Heliozoans/Centrohelida
These are united by the shared presence of alveoli which are membrane-bound sacs beneath the cell membrane
Alveolata
Name the three traditional phyla of Alveolata
Phylum Ciliiophora: alveoli produce pellicles
Phylum Dinoflagellata: alveoli produce thecal plates
Phylum Apicomplexa: parasites with alveoli that perform several functions
Enumerate some ciliates
Euplotes sp, Tetrahymena sp, Paramecium sp, Dileptus sp, Stentor sp, Zoothamnium sp, Vorticella sp
The most structurally diverse and specialized protozoans
Ciliates in Phylum Ciliophora
Give features of Ciliophora
Larger than most other protozoa; commensal and parasitic forms; usually solitary and motile, some are sessile and colonial; most free-living in freshwater or marine habitats
True or false: Ciliates have single nuclei
False, Ciliates are always multinucleated
What are the nuclei of Ciliates?
Macronuclei and micronuclei
Enumerate the differences between macronuclei and micronuclei of Ciliates
Genes are transcribed in macronuclei, but never in micronuclei; Macro- have metabolic and developmental functions, micro- have sexual reproduction and give rise to macronuclei after exchange with other micronuclei; Macro- divide amitotically, micro- divide mitotically
Name two symbiotic ciliates that live in the digestive tracts of ruminants, frogs and toads, respectively
Entodinium sp. (ruminants) and Nyctotherus sp. (frogs and toads)
This is a ciliate transferred via fecal contamination of food and water
Balantidium coli
This genus live in the digestive tracts of ruminants
Entodinium
Live in the digestive tracts of frogs and toads
Nyctotherus sp.
This genus is commonly studied as a typical free-living ciliate
Paramecium
Describe the form of Paramecium
- Slipper-shaped with blunt anterior and pointed posterior region;
- Asymmetrical appearance
- Pellicle may be ornamented, ridged, or papilla-like projections
- Trichocysts found within clear ectoplasm
True or false: Paramecium are autotrophic
False: They are generally holozoic; feed on bacteria, algae, and small organisms
How do Paramecium move?
Cilia beat forward or backward
How do Paramecium reproduce?
Through binary fission, conjugation, autogamy
Phylum of flagellates, half are photoautotrophic, half are colorless/heterotrophic
Dinoflagellata
Give some representatives of Dinoflagellates
Gymnodinium, Ceratium, Noctiluca, Pfisteria piscicida
What are the ecological significances of Dinoflagellates
Important primary producers in freshwater and marine environments
What group of Dinoflagellates live in mutualistic association with corals, anemones, and clams
Zooxanthellae
Dinoflagellate that is harmful and toxic to many organisms
Pfiesteria piscicida
All members are endoparasites
Apicomplexa
Apicomplexans have an ______ _______ that occurs only in certain developmental stages like the merozoites and sporozoites (responsible for their name)
Apical complex
These aid in penetrating host’s cells and are found in the apical complex
Rhoptries and micronemes
True or False: The locomotor organelles in Apicomplexans are quite obvious
False, but some stages have pseudopodia or flagella
Apicomplexan life cycle usually includes what?
Sexual and asexual reproduction
One life stage of an Apicomplexan which is a spore
Oocyst
A class of Apicomplexans which are intracellular parasites of invertebrates and vertebrates
Class Coccidea
Genus of Coccidea that causes coccidiosis
Eimeria
Enumerate three genera of Coccidea
Eimeria, Toxoplasma, Plasmodium
What are the symptoms of coccidiosis?
Severe diarrhea or dysentery
Species of Eimeria that is often fatal to young fowl due to intestinal pathogenesis
Eimeria tenela
Describe the life cycle of Eimeria once infecting a host
Undergoes schizogony in intestinal cells, produces gametes to form the zygote which develops into an oocyst, exiting via the feces
Parasite of cats with extraintestinal stages
Toxoplasma gondii
About one-third of world human population carries cysts of Toxoplasma gondii, mostly from eating ______
Undercooked meat
Can pose serious threats during pregnancy; about 2% of cases of mental retardation result from:
Congenital toxoplasmosis
Best-known coccidian and the most important infectious disease of humans
Plasmodium
Enumerate the four infectious species of Plasmodium
Plasmodium vivax
P. ovalae
P. malariae
P. falciparum
Which species of Plasmodium is the most common and fatal? What does it lead to?
P. falciparum; leads to cerebral malaria
The mosquito genus that carries all four forms of Plasmodium
Anopheles
Describe the life cycle of Plasmodium
Mosquito injects P. sporozoites present in their saliva; sporozoites penetrate liver cells and initiate schizogony; produces merozoites that penetrate more liver cells
What makes P. falciparum so fatal?
The sporozoites penetrate red blood cells after only one cycle
After digesting hemoglobin, Plasmodium release a dark, insoluble pigment called
Hemozoin
What causes the chills and fever of malaria?
The cyclic release of hemozoin and merozoites
More than ___ of people live in malarial regions
41%
Name the three phyla under Rhizaria
Cercozoa, Foraminifera, Radiolaria
This phylum under Rhizaria have no common body plan; can be amoeboid or flagellate
Phylum Cercozoa
Do Cercozoans have a common lifestyle?
No, they can be photosynthetic, heterotrophic, or parasitic
True or False: Cercozoa can be ameboid or flagellated
True, they can also be naked or testate
Ancient group of shelled amoebas found in all oceans, and in some fresh and brackish water
Foraminifera
Foraminiferans have what kind of pseudopodia?
Reticulopodia
Describe the complex life cycles of “forams”
Multiple fission and alternation of haploid and diploid generations
What kind of pseudopodia do Radiolarians have?
Axopodia
Radiolarians can have what kind of central capsule?
Ovoid, spherical, or branched
True or False: Radiolarians can separate their cytoplasm into inner or outer zones
True
Where do most Radioliarans live?
Mostly live in shallow water and pelagic ocean; some in deep water up to 1000 m
Clade Plantae is composed of three lineages. Name them
Glaucophytes (freshwater green algae), Rhodophytes (red algae), Viridplantae (formerly Chlorophyta and all land plants)
Give representative species of Viridiplantae (one single-celled biflagellate algae, three colonial algae, one multicellular algae)
Chlamydomonas sp., Gonium sp., Eudorina sp., Pandorina sp., Volvox sp.
These are amebas with flattened mitochondrial cristae and distinct axopodia with axoneme arranged in hexagonal or triangular sets
Centrohelida
Naked and testate amebas along with those that have flagellated life stages
Amebozoa
Physarum sp., Dictyostelium sp. are two genera under what subgroup? (plasmodial and cellular slime molds)
Mycetozoa
Arcella sp. is a type of what amoebozoa?
Testate amoeba with lobose pseudopodia
Give two species of naked lobose amebas
Amoeba proteus and Chaos carolinense
List common disease-causing amebozoans
Acanthamoeba castellani, Entamoeba histolytica
How is Acanthamoeba castellani spread?
Spread by contact lenses that are not properly disinfected
What are the effects of Entamoeba histolytica?
Lives in and invades the intestinal wall by secreting enzymes that attack the intestinal lining, leading to amebic dysentery. It is carried in the blood to the liver and other organs, causing more damage
What is characterized by a flattened mitochondrial cristae and one posterior flagellum on flagellated cells?
Clade Opisthokonta
Name some unicellular taxa of Opisthokonta
Microsporidians, Choanoflagellates
What taxon are the most likely sister group to animals?
Choanoflagellates
What are Microsporidians?
Intracellular parasitic fungi
What does the SAR group include?
Stramenopiles, Alveolata, Rhizaria
What does the Excavata group include?
Fornicata, Parabasalea, Heterolobosea, Euglenozoa
