Kingdom Protista Biology 11 Mr. McCallum

Introduction  Protista = the very first  Fossil records date back 1.5 billion years  Unicellular and multicellular  Do not have “true tissues” – cells working together  Eukaryotic  More “advanced” than bacteria  Discrete, membrane-bound nucleus  Contain organelles (ribosomes, mitochondria, lysosomes, etc.)  More efficient at using available nutrients and carrying of metabolic activities

Introduction (2)  Mostly live in water (can live in soil and human body)  Most are microscopic  Complex reproduction  Asexual, sexual, multiple  Organism that is not a plant, animal, or fungi  Group contains organisms that do not “fit” into the other 5 kingdoms

Classification  Artificial categories that do not reflect the evolutionary history of the organisms  Way that they obtain nutrition  Heterotrophic or autotrophic  Means of locomotion  Sessile (do not move) or mobile  Cilia, flagella, pseudopods, etc.

Plant-like Protists (Algae)  Autotrophic….(completely?)  Vary from simple one-celled organisms to large multicellular forms  Contain chlorophyll (pigmentation)  Traditionally termed algae – no longer holds taxonomic significance  Now: “photosynthetic organism that is either unicellular or multicellular without tissues”  Kingdom Eubacteria: cyanobacteria – blue-green algae  Kingdom Protista: red, brown, and green algae  6 phyla exist

1. Euglenophyta  Found mostly in fresh, stagnant waters  Over 800 species in ponds and lakes around the world  Autotrophic - obtain nourishment via photosynthesis  Heterotrophic (solid food consumption) during periods of darkness  Reproduce asexually  Euglena  Eyespots (light detection) and flagellum (locomotion)  Most have two flagella  No cell wall – have pellicle (firm and flexible covering under plasma membrane)  Vacuole for excess water removal

Euglena

2. Crysophyta (Golden-Brown Algae and Diatoms)  Found in both fresh and salt water  Autotrophs  Contain chlorophyll  Many are flagellated  Encased in shells/skeletons  Diatoms are the most abundant plant-like protist  Encased in thin silica shells

Diatomaceous Earth  Pest Control  Ground fine powder – damages externally, ruptures internal organs  Abrasives  Toothpaste – plaque removal  Bath products  Metal polish  Filtration  Hot tubs and swimming pools – fine structures  Indicator Species  Flourish in waters around the world  Used to determine health of ecosystem

3. Pyrrophyta (Dinoflagellates)  Autotrophs  Contain chlorophyll and red pigments  Important primary producers and a major component of oceanic plankton

Red Tides and Bioluminescence  Red Tides  Environmental impact?  Bioluminescence  Harmful?

4-6. Green (sea lettuce), Brown (kelp), and Red Algae (Irish moss)  Comprised of phyla Chlorophyta (green algae), Phaeophyta (brown algae), and Rhodophyta (red algae)  Primary food producers and the source of biological energy for most aquatic food webs  Supply about two thirds of the world’s oxygen  Unicellular and multicellular varieties  Large variety of pigmentation (all contain chlorophyll)  Complex reproduction – asexual, sexual, combination, fragmentation

Green, Brown, and Red Algae

TED talk: Jonathan Trent

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