Protists

Choanoflagellates

closest relatives of sponges. Heterotrophs

Algae description

photosynthetic protists in water with chloroplasts with chlorophyll a and carotenoids. like plants

Types of algae (photosynthetic)

euglenoids, dianflagellate, golden algae, brown algae, diatoms, red algae, green algae,

Heterotrophic fungi-ish but not close relatives

slime molds: plasmodial, cellular; water molds

Protozoa (unicellular) groups

Not based on DNA, but movement

Flagellated, Ciliates, Amoeboids, Apicomplesxes

Euglenoids

Type of algae (morphological group within morphological group)

unicellular, elongated w/ short flagellum, pellicle- layer of protective elastic or rigid protein strips; eye spot for light. 1/3 are photosynthetic. Some, like Euglena, are photosynthetic AND heterotrophic.

Dinoflagellates

Algae group (morphological group within morphological group)

2 flagella of dif lengths. Armor of overlapping cellulose plates. ½ photosynthetic. Live in tissues of marine animals and provide carbohydrates. Predaotros, parasites, bioliminscent.

Cause red tide bloom after nutrient boost. Can produce deadly toxins, which can infect shellfish.

Pfiasteria, Karlodinium

Golden algae

2 flagella, unicellular, sometimes filamentous or colonial. Some stack in chains like Dionbryon. food for zooplankton. toxic bloom. Photosynthetci except in low light

Diatoms

2-part silica cell walls like a shoebox. All moist habitats, but sensitive to pH and such. Remove CO2 and are food for zooplankton. Shells acumulate in ocean floor and are used in polish, filters, toothpaste, reflective signs and paints. Fossilize well- we know of 35,000 extinct species.

Brown algae

largest, most complex protists. Multicellular. Reproductive cells have 2 flagella. Marine habitats. Sargassum lives in Sargasso Sea in Atlantic. Kelps are the largest of them- get up to 30 meters. Laminaria digitata is a kind eaten by humans. Algin, a chemical from the cell walls, is used to stabalize, thicken, and emulsify ice cream, candy, chocolate, dressing, toothpaste, cosmetics, polishes, latex paint, paper.

Red algae

Many large, some micro. Store starch and chlor. a like green algae. Can live deeper- 200 meters, due to red and blue pigments. Agar is a polysacharide used for canned meats, ice cream, yogurt, and culture medium in petri dishes. Nori is a sushi wrap. Carrageenan is an emulsifier in chocolate bars, paints, cosmetics, and creamy foods.

Green algae

Most similar to plants: chlorophyll a and b, starch, cellulose, alternation of generations- haploid gametophyte and diploid sporophyte. Live in freshwater or most land, but some are symbionts with fungi (lichen). One kind is th smallest eukaryote.

Types of green algae

Micromonas is the smallest eukaryote at 1 micro m, and Ulva is 1-meter-long sea lettuce. Can be all the cellulars, rootlike parts but not as specialized as true plants. Chlamydomonas is sexual and ace. Volvox form hollow balls that form colonies within them until bursting. Micrasterias- desmids; Acetabularia- mermaid’s wineglass; Spirogyra- ribbonlike. Chlorella being considered for food and oxygen on space flights.

Slime molds include

plasmodial slime mold and cellular slime mold

Plasmodial slime mold

Feeding stage: plasmodim- a huge cell with thousands of diploid nuclei in one cell membrane. Up to 25 cm diameter. In famine: forms fruiting body with thick-walled reproductive spores, which germinate when conditions ameliorate- they will fuse to form diploid zygote, then divide nucleuos by mitosis.

Cellular slime mold

Individual cells retain membranes through life cycle. Haploid amoebae when feeding. Famine: secrete chemicals to aggregate into a sluglike thing that moves to light and forms a stalk with a fruiting body that produces haploid spores. Stalk perishes- spores germinate into haploid amoebae.

Dictyostelium discoideum.

Dictyostelium discoideum.

a type of cellular slime mold.

Cell moves by extensions that also engulf.

Cytokinesis uses myosin.

Chemotaxis where they move toward one another through signals when starving

Differentiation when they come together: spores, stalk

Water molds / oomycetes

decomposers, parasites. Filaments secrete digestive enzymes. Like fungi chytrids, they produce swimming spores that disperse in water and wet soil. Different: diploid rather than haploid fungal filaments. Cellulose rather than chitin fungi walls. Diseases.

Water mold examples and the diseases they cause

Phytophthora infestans eg plant desytroyer blight in potatoes. Phytophthora ramorum tree oak death. Saprolegnia forms cottony masses on fish

Flagellated protozoa description

UNICELLULAR PROTISTS WITH ONE OR MORE FLAGELLA; FREE LIVING IN SOIL OR WATER; parasites

Amoeboid protozoa description

Unicellular protists that use pseudopodia in locomotion and feeding. Useful in dating rock strata

Ciliates description

unicellular protists with cilia covering the cell surface. oral crease, food vacuoles, anal pore. Contractile vacuole regulates osmosis. 2 nuclei- micro division, macro development. 1/3 are symbiotes in cattle and aquatics.

Apicomplexans description

Unicellular, nonmotile protists that are parasites of animals; cells have apical complex at one end

Flagellated examples

Trichonympha lives in termites and digest cellulose.

Trichomonas vaginalis in urogenital tracts causes vaginitis in females

Giardia intestinalis / lamblia causes hiker’s diarrhea aka giardiasis from cysts in water.

Trypanosomes (whip-shaped that invade blood and brain): Trypanosoma brucei causes African sleeping sickness. Trypanosoma cruzi causes Chagas disease. Leishmania from sand flies

Amoeboid examples

Amoeba proteus engulfs bacteria, algae, other protists with pseudopods.

Entamoeba histolytica causes fever and diarrhea

Foraminiferans/forams: calcium carbonate shells- very abundant, 1/3 of ocean made of Globigerina

Radiolarians: oldest protozoa- planktonis with silica tests and pseodopodia. Make radiolarian ooze as thick as 400 meters from sediment of their tests

Ciliates examples

Paramecium and its predator Didinium are free-living and motile. Stentor is an attached form. Ichthyophthirius multifilis causes ich in freshwater fish (like in aquariums)

Apicomplexan examples

Cryptosporidium causing waterborne diseases- even in pools. Toxoplasma gondii in cat feces can infect people and cause brain, eye, and fetus issues w/ cysts. For Plasmodium species cause malaria, which has a cycle of sporozoites, merozoites, and gametocytes in a person’s bloodstream.

5 Supergroups of eukarya

Based on genetics

Archaeplastida, SAR, Opisthokonta, amoebazoa, excavata

Archaeplastida

Supergroup

chloroplasts from primary endosymbiosis

ex: red algae, green algae, land plants

Opisthokonta

motile cells with one flagellum, may have chitin

includes: chanoflagellates, animals, fungi

SAR

Supergroup

Molecular similarities

Stramenpiles: motile cells w/ two flagella- one has tubular hairs; flucoxanthin. Ex: diatoms, brown algae, gold algae, water molds

Alveolates: alveoli (flattened sacs) beneath membrane. Ex: ciliates, dinoflagellates, ampicomplexans

Rhizaria: Amoeboid movement, many produce shells. Ex: foraminiferans, radiolarins

Amoebazoa

Amoeboid movement via pseudopodia; feed by phagocytosis; slime molds form spores

Includes: amoeba, slime molds

Excavata

Supergroup

Unicellular, flagellated protists; may lack mitochondria; photosynthetic or parasitic; chloroplasts (when present) are derived from secondary endosymbiosis

Euglena, Giardia, Trichonympha, Trichomonas,