BIOL 420 1st Edition Lecture 5Current LectureKingdom ProtistaText Reference: Chapter 15 Kingdom Protista- Protozoa – “animal-like” protists- Slime molds – “fungi-like” protists- Algae – “plant-like” protistsKingdom Protista represents a polyphyletic Kingdom *protozoa – all heterotrophic but all are single celled protists. Photosynthetic Protists – algae (heterotrophs) and seaweedsAncestry of algae:Grypaniaspiralis, 2.1 billion years old; 1st eukaryotic algae, Measure ½ meter in length and 2mm.Fossil. They think the spirial like figure is algae that was grown back at this time period. Bangiomorpha, 1.2 billion years old, oldest algal fossil definitely related (perhaps identical) to modern algae Bangia. IndistinctionalEuglena: single celled, lives in freshwater, evolved from phagocytic ancestors. engulfes food, contains a flagellum, stigma – eyes pod, helps detect light; photosynthetic Algae and seaweeds – photosynthetic producers in aquatic habitats- Simpler bodies than plants and other differencemersPhytoplanktonThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Survey of Photosynthetic ProtistsPhylum Euglenophyta (Euglena)- Ancestors may have been phagocytic heterotrophs- Chloroplast- Flagella- Chlorophyll a and b- 2/3 of Genera actually colorless heterotrophs- Unicellular- No cell wall- Pellicle: gives some kind of structure but gives flexibility- Stigma- Contractile vacuole- Paramylon starch- Pyrenoid- Nucleus- Reproduction by mitosis /no sexual reproductionPhylum CryptophytaCryptomonads- “Hidden”- Single celled flagellates- May have arisen from the fusion of two eukaryotic cells- Marine and fresh waterDinoflagellates- Closely related to ciliated protozoa like Paramecium- Two flagella, perpendicular- Permanently condensed chromosome- Reproduce by longitudinal cell division- Many armored- Singled celled- Many mixotrophic – can function as autotroph or heterotroph- About ½ lack photosynthesis- Many live independently but many more occur as symbionts in sponges, jellyfish, sea anemones, corals, and octopus- Zooanthellae– symbiotic dinoflagellates that appear as golden, spherical cells- Responsible for growth of coral reefs, coral polyps- “red tides” – Gonyaulax ( northeastern Atlantic) affect fish, mussels, oysters, clams Diatoms- Unicellular (single) responsible for ¼ of all global carbon dioxide fixation- 12,000 species, 285 genera- 2 piece, silica shell like a petri dish- Pennate diatoms- Centric diatoms- Diatomaceous earth- Oxygen collects inside of the sellBrown Algae - 1500 species- Mainly marine- Dominate rocky shores throughout cooler regions of the world- Taxonomic importance of pigments and starch- Brown algae – chlorophyll a and c ,fucoxanthin pigment that gives brown algae characteristic brown or olive-green color- Laminarin starch- Mannitol- Includes kelps and rockweeds- ExamplesFucus(rockweed)Laminaria (kelp) - Sargassum - floats, can find it along the shore. Blade – analogous to leaves; Macrocystis(kelp) – can grow up to 12ft. harest for animal feeding in some parts of the world, industrial productsEctocarpusNereocystis(kelp)- Body plan (Sargassum as an example)ThallusStipeAir bladderBlade- Body plan (Laminariaas an example)StipeBladeHoldfast- Body plan (Ectocarpusas example)Branched filaments- Body plan (Macrocystis as example)True tissuesSieve tubes- Life cycle (Laminaria) – very short gametophyte stag, cell that can produce eggs  zygote  dividing to form conspicuous generationAlternation of generationSporophyte (conspicuous)Gametophyte*these stages BELOW is to help transfer asexual to sexual stages are an advantage. As animals traveled to land they had to rethink the transfer of these stages. Due to evolution Haploid – one set of chromosome, gametophyte (sexual reproduction stage – all off springs are alike)Diploid – two sets of chromosome, sporophyte (asexual stage – only takes one to reproduce – high level of off springs – the conspicuous generation)ZoosporesOogoniumZygote- Life cycle (Fucus)ReceptaclesConceptaclesAntheridiaOogoniumZygoteRed Algae (Phylum Rhodophyta)- 6,000 species- Tropical and warm waters- Mostly multicellular, only a few unicellular- Abundant marine, a few freshwater- Phycobilins give characteristic red color- Floridean starch- Commercial importanceAgarCarrageenans- ExamplesCoralline algae – looks like another piece of animal, the hard shell protects against herbivore PolysiphoniaChondrusPorphyraGreen Algae- 17,000 species- a lot more diversity and forms- Mostly aquatic but found growing in snow, on tree trunks, and as symbionts with sponges, cnidarians, lichens- Ancestors of plants- ExamplesChlamydomonasVolvox– steroid, asexually or sexually produceUlvaAcetabularia– single celled organismSpirogyra– zig-zagDesmids- Life cycle (example Chlamydomonas) – single celled algae, - Mirror images of each otherZoosporesZygote- Life cycle (example Volvox)SpheroidsDaughter coloniesSexual inducer molecule- Life cycle (example Ulva) – can’t tell the gametophyte stage from the somotophyte