Unicellular Eukaryotes and Protistology Vocabulary Flashcards

Comprehensive vocabulary flashcards covering terms, anatomical features, taxonomic classifications, life cycle stages, and species descriptions of unicellular eukaryotes based on the lecture notes.

Ontogeny

The origin and development of an individual organism, from fertilization through its mature form.

Phagotrophy

Acquiring food by engulfing particles or prey; characteristic of Amoebozoans.

Osmotrophy

Acquiring nutrients by absorption rather than engulfment.

Schizogony

Repeated asexual division used by Plasmodium and related organisms to rapidly increase in number.

Sporogony

Formation of resistant, spore-like stages used for transmission between hosts.

Kinetoplast

A dense mass of DNA within a single large mitochondrion; unique to organisms in Kinetoplastida such as Trypanosoma and Leishmania.

Pellicle

A flexible protein-based outer covering distinct from a rigid cell wall, allowing euglenoid movement in Euglena.

Conjugation

A sexual process in ciliates involving the exchange of micronuclei between two individuals.

Encystation

The process where a microorganism forms a protective wall around itself to become a dormant cyst.

Excystation

The process where an organism breaks out of its cyst to return to its active form.

Trophozoite (Entamoeba histolytica)

The active, feeding form of Entamoeba histolytica possessing a single nucleus.

Cyst (Entamoeba histolytica)

The resistant form of Entamoeba histolytica; the mature cyst contains four nuclei.

Stigma

A reddish eyespot near the anterior end of Euglena sp. used to detect the direction of light.

Mixotrophic

A mode of nutrition where an organism can photosynthesize in the presence of light and absorb nutrients when light is unavailable.

Longitudinal binary fission

A form of asexual reproduction in which the cell divides lengthwise rather than across its width, as observed in Euglena sp.

Undulating membrane

A wave-like extension running along the length of the body connected to the flagellum in Trypanosoma sp.

Zooids

Individual cells arranged across the surface of a Volvox sp. colony, connected by fine protoplasmic strands.

Schizont

The stage of Plasmodium sp. undergoing schizogony, or repeated asexual division.

Microgametocyte

The male sexual stage of Plasmodium sp. visible on a blood smear.

Macrogametocyte

The female sexual stage of Plasmodium sp. visible on a blood smear.

Cytostome

The cell mouth where food is drawn in by ciliary action, present in ciliates such as Paramecium sp. and Balantidium coli.

Macronucleus

The larger type of nucleus in Paramecium sp. responsible for metabolic functions.

Micronucleus

The smaller type of nucleus in Paramecium sp. involved in reproduction and exchanged during conjugation.

Peristome

A wide rim at the top of the body of Vorticella sp. surrounding the oral disc.

Amoeba sp.

A unicellular eukaryote with no fixed body shape, lobose pseudopodia, and a contractile vacuole for osmoregulation, reproducing asexually by binary fission.

Entamoeba histolytica

A parasitic amoebozoan existing as a single-nucleus trophozoite or four-nucleus mature cyst, and the causative agent of amebiasis.

Euglena sp.

A green, spindle-shaped unicellular eukaryote with a flagellum arising from an anterior reservoir, a stigma, a flexible pellicle, and mixotrophic nutrition.

Trypanosoma sp. (Trypanosoma brucei)

A colorless, spindle- or leaf-shaped kinetoplastid parasite with an undulating membrane; causative agent of Human African Trypanosomiasis (African Sleeping Sickness) transmitted by the tsetse fly.

Volvox sp.

A large, hollow, spherical green colony made up of hundreds to thousands of zooids connected by protoplasmic strands.

Plasmodium sp.

An apicomplexan parasite lacking locomotory organelles, transmitted by female Anopheles mosquitoes, and the causative agent of malaria.

Paramecium sp.

A slipper-shaped ciliate entirely covered in cilia, swimming at speeds of $1\text{ to }3\text{ millimeters per second}$, possessing a macronucleus, micronucleus, and oral groove.

Vorticella sp.

A bell-shaped sessile ciliate attached to a substrate, featuring a long contractile stalk that coils tightly like a spring when disturbed.

Balantidium coli

The largest ciliate in the set, oval in shape with full ciliation but no stalk; the only ciliate known to parasitize humans and causative agent of balantidiasis.

Giardia lamblia

A waterborne parasite whose trophozoite has two nuclei (giving a paired appearance) and whose oval cyst has four nuclei; causative agent of giardiasis.

Trichomonas vaginalis

A pear-shaped protozoan with a shorter undulating membrane that lacks a cyst stage; causative agent of a sexually transmitted infection.

Naegleria fowleri

A free-living protozoan in warm freshwater with an amoeboid form and temporary flagellate stage; causative agent of primary amoebic meningoencephalitis.

Toxoplasma gondii

A parasite featuring crescent- or banana-shaped tachyzoites with cats serving as the definitive host; poses risk during pregnancy.

Leishmania sp.

A kinetoplastid parasite occurring as an amastigote form inside macrophages and a flagellated promastigote form in its sandfly vector.

Stentor sp.

A large, trumpet- or horn-shaped ciliate with a distinctive beaded (moniliform) macronucleus.

Didinium sp.

A barrel-shaped ciliate with a protrusible proboscis at the anterior end that preys on Paramecium.