3Definitions: Prokaryotes: Unicellular organisms whose cells do not have a nucleus or other organelles, simpleEukaryotes:Unicellular or multicellular organisms with cells possessing a nucleus and other organelles that are enclosed by membranes
4Definitions: Nutrition: Process by which an organism obtains from its environment1. Energy2. Chemical elements (carbon)needed for its survival and growth.
5Definitions: 1. Energy Phototroph: organisms using sunlight as a source of energyChemotroph:organisms using chemicals as a source of energyi.e. hydrogen sulfide, ammonia, methane gas
6Definitions: 2. Obtain Carbon molecules Autotroph: organisms capable of synthesizing their own food from simple inorganic molecules (e.g. carbon from CO2)Heterotroph:organisms that obtain food from organic compounds (i.e. other living organisms) (e.g. carbon from glucose)
7Definitions: Primary Producers organisms that manufacture organic matter from CO2, usually by photosynthesis
9Domain Archaea Oldest group of organisms (3.8 billion years) Prokaryotic cellsDNA analysis – more closely related to eukaryotesHeterotrophs or Autotrophsimportant decomposers, nitrogen fixers
10Domain Archaea Autotrophs: “extremophiles” Methanogens – chemoautotrophs that produce methane gas from CO2 and hydrogen gas.Halophiles – live in high salt environments, some are photoautotrophs (performing photosynthesis)Thermophiles – live in environments of very hightemperatures, like hot springs or near hydrothermal vents.
11Domain Bacteria Structure: unicellular Size ranges from 0.5 to 15 μm, among smallest living organismsProkaryotic cellsShapes include: spheres, spirals, rods, and ringsReproduction:Simple asexual divisionGeneration time = 1-3 hrs.
12Domain Bacteria Most are heterotrophs - important decomposers, some are nitrogen fixers- degrade pollutantsSome are Autotrophs:Photosynthetic bacteria contain chlorophyll aChemosynthetic bacteria use energy released bybreakdown of ammonia, hydrogen sulfide and other sulfur or iron compounds
13Domain Bacteria Cyanobacteria (formerly “blue-green algae”) most primitive plant-like organismsPhotoautotrophic bacteriaProkaryotic cellsPigments: chlorophyll a, phycocyanin, and phycoerythrinImportant role in O2 accumulation in our atmosphere, somecarry out nitrogen fixationSolitary or colonial****DRAWING****
15Kingdom Protista General information: Often separated into many different KingdomsVariation in cellular anatomy, ecological role, andlife cyclesPlanktonic, unicellular, and multicellularStructure:Mostly unicellular – complex an organism as anywhole plant or animalSize range: 0.8 to 2,000 μm (=2mm), larger thanbacteria
16Kingdom Protista Feeding: Some are photoautotrophs phytoplankton Some are heterotrophs zooplanktonOthers are mixotrophs Euglena sp.Locomotion:Flagella or cilia
17Kingdom Protista Phytoplankton: Make up ~1% of global chlorophyll biomass, but are responsible for ~50% global photosynthesisAre the base of the oceanic food webRegulate global climateSink for atmospheric CO2Chl a Absorbance
18Photosynthetic Protists: Diatoms: (Class Bacillariophyta)~ 12,000 species, half are marineUnicellular, but aggregateCentric (cylindrical): planktonicPennate (boat-shaped): benthicEnclosed by cell walls made ofsilica (SiO2)Yellow and brown color carotenoid pigment is fucoxanthinFig. 5.5
19Photosynthetic Protists: Diatoms“Shell” Frustulelight passes through holesperforations allow gasses and nutrientsFrustules of dead diatoms diatomaceous oozeImportant primary producers – temperate and polar regionsCan produce domoic acidReproduction:Asexual = Cell divisionSexual egg + sperm in auxospore stage****DRAWING****
20Photosynthetic Protists: Dinoflagellates: (Class Dinoflagellata)~ 1,200 species, all marineImportant primary producers –Warm regionsUnicellular2 unequal flagellaExternal cell wall armoredwith plates made of cellulose or nakedHave chlorophyll, can also ingest food particlesHave Chlorophyll a, Chlorophyll c2, and peridininFig. 5.7Gonyaulax polyedra
21Photosynthetic Protists: DinoflagellatesMassive blooms cause “red tides”Some release toxins that cause shellfishpoisoning (PSP, NSP, DSP)Some bioluminesceSome are symbiotic to other organisms and called zooxanthellae****DRAWING*****Photo by DC Tulipani, 8/2003Zooxanthellae from anemone, Bartholomea annulata
25Photosynthetic Protists: Coccolithophores: (Class Haptophyta)Covered with small calcareous coccolithsFlagellatesMajor source of primary production<20µm in diameter
26Non-photosynthetic Protists (Zooplankton): Foraminiferans: (Phylum Granuloreticulosa)foramen = little hole, ferre = to bearPlanktonic protozoans (animal-like protists),exclusively marineShells (tests) made of calcium carbonate(CaCO3)“Amoeba with a shell”PseudopodiaShells of planktonic forams sink to bottom toform foraminiferan ooze
27Non-photosynthetic Protists: ForaminiferansMost live on bottom, free or attachedImportant contributors in coral reefs and sandy beaches (Bermuda’s “pink” beaches)****DRAWING****
29Non-photosynthetic Protists: Radiolarians (Phylum Polycystina)Planktonic, marineSecrete tests made of silica (SiO2)Tests typically spherical withradiating spinespsuedopodia – diatoms (Why?)Open waters throughout oceanShells settle to bottom and form siliceous ooze, called radiolarian ooze****DRAWING****Fig. 5.11
30Non-photosynthetic Protists: Genus Euglena~150 species, freshwaterFlagellum used for locomotionMixotrophs:Contain chlorophyll photosynthesizeSome eat small particles of living matterEuglena acusEuglena spirogyra
31Photosynthetic Protists: Multicellular Algae General Structure:More complex than unicellular algaeStill lack the highly specialized structures and reproductive mechanisms of land plantsFig. 6.1
32Photosynthetic Protists: Multicellular Algae Phylum Chlorophyta: “Green algae”Contain chlorophyll a – no pigment to maskUnicellular (3 examples - DRAWINGS)DesmidsVolvox sp.Cladophora sp.Multicellular (2 examples - DRAWINGS)Ulva sp.Codium sp.Ulva sp.Codium fragile
33Photosynthetic Protists: Multicellular Algae Class Phaeophyta: “Brown algae”Multicellular, mostly marineOlive-green to dark brown color from carotenoid pigment: FucoxanthinAlso have chlorophyll a and cOften dominant primary producers on temperate and polar rocky shores2 examples - DRAWINGSMacrocystis pyriferaEgregia sp.
35Photosynthetic Protists: Multicellular Algae Phylum Rhodophyta: “Red algae”Essentially marine, all multicellularCommon, more species than green/brown combinedContain red pigments called phycobilinsMost are soft bodied,some coralline reds encrusted with hard calcium carbonate, Why?2 examples – DRAWINGSCorallina sp. (calcified)