Lecture 13 - Protists

Vocabulary flashcards summarizing major terms, organisms, structures, and diseases covered in the Protista lecture notes.

Protist

Any eukaryotic organism in Kingdom Protista; not a fungus, plant, or animal.

Characteristics of Protists

Mostly unicellular (some multicellular), various nutrition modes, predominantly aquatic or moist habitats, free-living or parasitic.

Mitosis (in protists)

Asexual division where one cell splits into two identical daughter cells.

Schizogony

Multiple fission; nucleus divides repeatedly before the cell splits into many daughter cells.

Fragmentation

Asexual reproduction where a broken piece grows into a new organism.

Conjugation (protists)

Sexual process in which opposite mating strains pair and exchange genetic material.

Gametocyte

Haploid reproductive cell that fuses with another to form a diploid zygote.

Algae

Plant-like protists that are photoautotrophic and often possess chlorophyll.

Protozoa

Animal-like protists that ingest food by phagocytosis and lack cell walls.

Molds (fungus-like protists)

Water molds, white rusts, and downy mildews; filamentous, heterotrophic protists.

Phycology

The scientific study of algae.

Flagellum

Long whip-like appendage used for locomotion; many algae possess them.

Photoautotroph

Organism that uses light energy to synthesize organic compounds from CO₂.

Chloroplast

Organelle containing chlorophyll where photosynthesis occurs.

Phylum Chlorophyta

Green algae; share chlorophyll a & b, cellulose cell walls, starch storage.

Chlamydomonas

Unicellular green alga with two flagella and a cup-shaped chloroplast.

Volvox

Colonial green alga forming hollow spheres of flagellated cells.

Ulva

Multicellular green alga known as sea lettuce; body two cells thick.

Prototheca moriformis

Colorless, chemoheterotrophic alga that causes protothecosis.

Protothecosis

Skin infection in humans/animals produced by Prototheca spp.

Phylum Chrysophyta

Diatoms; algae with silica cell walls that fit like a box and lid.

Diatomaceous earth

Sedimentary deposit of diatom shells used as an abrasive.

Phylum Phaeophyta

Brown algae (kelp); large multicellular seaweeds.

Kelp

Large brown algae such as Macrocystis and Laminaria.

Thallus

Body of a kelp composed of stipe and blade but lacking true tissues.

Stipe

Stem-like portion of a kelp thallus.

Blade (kelp)

Leaf-like photosynthetic portion of kelp.

Holdfast

Root-like structure anchoring kelp to substrates.

Air bladder

Gas-filled float that lifts kelp blades toward light.

Macrocystis

Giant kelp genus within brown algae.

Laminaria

Genus of brown algae with medicinal algin uses.

Phylum Pyrrophyta

Dinoflagellates; two flagella, cellulose plates, often bioluminescent.

Dinoflagellate

Spinning, often toxic algae responsible for red tides.

Bioluminescence

Light production by living organisms, common in some dinoflagellates.

Red tide

Toxic algal bloom of dinoflagellates that can contaminate shellfish.

Phylum Rhodophyta

Red algae containing phycobilin pigments enabling deep-water photosynthesis.

Phycobilin

Accessory pigment in red algae absorbing blue/green light.

Agar

Polysaccharide from red algal cell walls; used as microbiological solidifier.

Trophozoite

Active, feeding, motile stage of a protozoan.

Cyst (protozoan)

Dormant, protective form enabling survival outside hosts.

Phylum Amoebozoa

Protozoans that move via pseudopodia.

Pseudopodium

Temporary cytoplasmic extension for movement and feeding.

Entamoeba histolytica

Amoebozoan causing amoebic dysentery in humans.

Amoebic dysentery

Intestinal disease with ulcers and diarrhea caused by E. histolytica.

Phylum Euglenozoa

Flagellated protozoans including Giardia and Trypanosoma.

Giardia lamblia

Flagellate causing giardiasis (backpacker’s disease).

Giardiasis

Intestinal infection with diarrhea from Giardia ingestion.

Trypanosoma brucei

Flagellate causing African sleeping sickness.

African sleeping sickness

CNS disease transmitted by tsetse fly bites; caused by T. brucei.

Tsetse fly

Blood-sucking vector transmitting T. brucei.

Trypanosoma cruzi

Protozoan causing Chagas disease.

Chagas disease

American trypanosomiasis transmitted by triatomine bugs.

Triatomine bug

Insect vector (kissing bug) that spreads Trypanosoma cruzi.

Phylum Apicomplexa

Non-motile, intracellular parasitic protozoans with apical complexes.

Plasmodium

Apicomplexan genus causing malaria in humans.

Malaria

Mosquito-borne disease with cyclic fever and anemia caused by Plasmodium.

Merozoite

Asexual daughter parasite that invades red blood cells in malaria.

Sporozoite

Infective stage of Plasmodium transmitted by mosquitoes.

Definitive host

Organism where a parasite’s sexual reproduction occurs (mosquito for malaria).

Intermediate host

Organism where a parasite’s asexual stages occur (human for malaria).

Antimalarial drugs

Medications targeting blood-stage Plasmodium to treat or prevent malaria.

Water mold

Fungus-like protist belonging to oomycetes; decomposers or parasites.

Plasmopara viticola

Water mold causing downy mildew of grapes.

Downy mildew (grape)

Plant disease of grapes produced by Plasmopara viticola.

Phytophthora infestans

Water mold responsible for potato late blight and Irish Potato Famine.

Late blight of potato

Devastating disease of potatoes caused by Phytophthora infestans.