Bacteria, Protists, Algae, and Marine Plants ENV 121 Lab

Tree of Life Figure 4.24

Definitions: Prokaryotes: Unicellular organisms whose cells do not have a nucleus or other organelles, simple Eukaryotes: Unicellular or multicellular organisms with cells possessing a nucleus and other organelles that are enclosed by membranes

Definitions: Nutrition: Process by which an organism obtains from its environment 1. Energy 2. Chemical elements (carbon) needed for its survival and growth.

Definitions: 1. Energy Phototroph: organisms using sunlight as a source of energy Chemotroph: organisms using chemicals as a source of energy i.e. hydrogen sulfide, ammonia, methane gas

Definitions: 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)

Definitions: Primary Producers organisms that manufacture organic matter from CO2, usually by photosynthesis

Tree of Life Figure 4.24

Domain Archaea Oldest group of organisms (3.8 billion years) Prokaryotic cells DNA analysis – more closely related to eukaryotes Heterotrophs or Autotrophs important decomposers, nitrogen fixers

Domain 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 high temperatures, like hot springs or near hydrothermal vents.

Domain Bacteria Structure: unicellular Size ranges from 0.5 to 15 μm, among smallest living organisms Prokaryotic cells Shapes include: spheres, spirals, rods, and rings Reproduction: Simple asexual division Generation time = 1-3 hrs.

Domain Bacteria Most are heterotrophs - important decomposers, some are nitrogen fixers - degrade pollutants Some are Autotrophs: Photosynthetic bacteria contain chlorophyll a Chemosynthetic bacteria use energy released by breakdown of ammonia, hydrogen sulfide and other sulfur or iron compounds

Domain Bacteria Cyanobacteria (formerly “blue-green algae”) most primitive plant-like organisms Photoautotrophic bacteria Prokaryotic cells Pigments: chlorophyll a, phycocyanin, and phycoerythrin Important role in O2 accumulation in our atmosphere, some carry out nitrogen fixation Solitary or colonial ****DRAWING****

Domain Bacteria Prochlorococcus Synechococcus

Kingdom Protista General information: Often separated into many different Kingdoms Variation in cellular anatomy, ecological role, and life cycles Planktonic, unicellular, and multicellular Structure: Mostly unicellular – complex an organism as any whole plant or animal Size range: 0.8 to 2,000 μm (=2mm), larger than bacteria

Kingdom Protista Feeding: Some are photoautotrophs  phytoplankton Some are heterotrophs  zooplankton Others are mixotrophs  Euglena sp. Locomotion: Flagella or cilia

Kingdom Protista Phytoplankton: Make up ~1% of global chlorophyll biomass, but are responsible for ~50% global photosynthesis Are the base of the oceanic food web Regulate global climate Sink for atmospheric CO2 Chl a Absorbance

Photosynthetic Protists: Diatoms: (Class Bacillariophyta) ~ 12,000 species, half are marine Unicellular, but aggregate Centric (cylindrical): planktonic Pennate (boat-shaped): benthic Enclosed by cell walls made of silica (SiO2) Yellow and brown color  carotenoid pigment is fucoxanthin Fig. 5.5

Photosynthetic Protists: Diatoms “Shell”  Frustule light passes through holes perforations allow gasses and nutrients Frustules of dead diatoms  diatomaceous ooze Important primary producers – temperate and polar regions Can produce domoic acid Reproduction: Asexual = Cell division Sexual  egg + sperm in auxospore stage ****DRAWING****

Photosynthetic Protists: Dinoflagellates: (Class Dinoflagellata) ~ 1,200 species, all marine Important primary producers – Warm regions Unicellular 2 unequal flagella External cell wall armored with plates made of cellulose or naked Have chlorophyll, can also ingest food particles Have Chlorophyll a, Chlorophyll c2, and peridinin Fig. 5.7 Gonyaulax polyedra

Photosynthetic Protists: Dinoflagellates Massive blooms cause “red tides” Some release toxins that cause shellfish poisoning (PSP, NSP, DSP) Some bioluminesce Some are symbiotic to other organisms and called zooxanthellae ****DRAWING***** Photo by DC Tulipani, 8/2003 Zooxanthellae from anemone, Bartholomea annulata

http://www.whoi.edu/redtide/

Photosynthetic Protists: Coccolithophores: (Class Haptophyta) Covered with small calcareous coccoliths Flagellates Major source of primary production <20µm in diameter

Non-photosynthetic Protists (Zooplankton): Foraminiferans: (Phylum Granuloreticulosa) foramen = little hole, ferre = to bear Planktonic protozoans (animal-like protists), exclusively marine Shells (tests) made of calcium carbonate (CaCO3) “Amoeba with a shell” Pseudopodia Shells of planktonic forams sink to bottom to form foraminiferan ooze

Non-photosynthetic Protists: Foraminiferans Most live on bottom, free or attached Important contributors in coral reefs and sandy beaches (Bermuda’s “pink” beaches) ****DRAWING****

http://earthguide. ucsd. edu/earthguide/imagelibrary/orbulinauniversa http://earthguide.ucsd.edu/earthguide/imagelibrary/orbulinauniversa.html http://www.ucl.ac.uk/GeolSci/micropal/foram.html

Non-photosynthetic Protists: Radiolarians (Phylum Polycystina) Planktonic, marine Secrete tests made of silica (SiO2) Tests typically spherical with radiating spines psuedopodia – diatoms (Why?) Open waters throughout ocean Shells settle to bottom and form siliceous ooze, called radiolarian ooze ****DRAWING**** Fig. 5.11

Non-photosynthetic Protists: Genus Euglena ~150 species, freshwater Flagellum used for locomotion Mixotrophs: Contain chlorophyll  photosynthesize Some eat small particles of living matter Euglena acus Euglena spirogyra

Photosynthetic Protists: Multicellular Algae General Structure: More complex than unicellular algae Still lack the highly specialized structures and reproductive mechanisms of land plants Fig. 6.1

Photosynthetic Protists: Multicellular Algae Phylum Chlorophyta: “Green algae” Contain chlorophyll a – no pigment to mask Unicellular (3 examples - DRAWINGS) Desmids Volvox sp. Cladophora sp. Multicellular (2 examples - DRAWINGS) Ulva sp. Codium sp. Ulva sp. Codium fragile

Photosynthetic Protists: Multicellular Algae Class Phaeophyta: “Brown algae” Multicellular, mostly marine Olive-green to dark brown color from carotenoid pigment: Fucoxanthin Also have chlorophyll a and c Often dominant primary producers on temperate and polar rocky shores 2 examples - DRAWINGS Macrocystis pyrifera Egregia sp.

Pelagophycus Pelagophycus Macrocystis Egregia

Photosynthetic Protists: Multicellular Algae Phylum Rhodophyta: “Red algae” Essentially marine, all multicellular Common, more species than green/brown combined Contain red pigments called phycobilins Most are soft bodied, some coralline reds encrusted with hard calcium carbonate, Why? 2 examples – DRAWINGS Corallina sp. (calcified)

Pelagophycus Halimeda Porphyra