Biology 11Mr. Wolfe

Algae

Taxonomic ClassificationMorphology / AnatomyLife History / Life CycleMorphogenesis / GrowthCommunities / EcosystemsInteractions / SymbiosisPhotosynthesisNutrient-Uptake RequirementsTemperature and SalinityWater MotionPollutionCultivation

Contents of Algae Notes

Can be single-celled and microscopicMost important food producers in their ecosystemsHabitat for many microscopic animalsIn freshwater, algae can form “pond scum” and

green “hairy” growth on submerged objectsBlooms of diatoms may give a brownish colourSingle cells often form chains or filamentsSome unicellular algae can swim like animalsThey contain chlorophyll and perform

photosynthesisAlgae produce dissolved O2 as waste, but when in

decay they deplete O2 and cause “summer die-off”

The Simplest of Plants

Unable to fit all algae into the Kingdom Plantae

Overlap occurs in habitat, structures, and physiology

Algae is often in symbiosis with other organismi.e. Corals and Lichen

The taxonomic classification will continue to evolve

The challenges with Algae

Green AlgaeBlue-Green AlgaeStonewortsEuglenoidsDinoflagellatesDiatoms

Major Groups of Freshwater Algae

Green Algae

Species are either marine or freshwater basedCells have a nucleiOccur as single cells, round and flattened

colonies, or as filaments. Some are mobile with flagella.

Pigments are in distinct bodies, plastids or chloroplasts

Most abundant of the pond algaeExamples: Chlamydomonas, Euglena,

Chlorella, Volvox

Green Algae

“Blue-Green Algae”

They were incorrectly labeled as algaeCyanobacteria are true prokaryotes and

members of the domain Bacteria – largest among them

They are aerobic photosynthesizersSpecialized cells: heterocyst for nitrogen

fixation3 basic types of morphology

Unicellular (i.e. Synechocystis)Forming round/square chains (i.e. Anabaena)Forming loose colonies in gelatinous material

(i.e. Gleocapsa)

“Blue-Green Algae”

Spirulina health supplementsEaten by the Aztecs, people on the shores of Lake ChadCultivated in Hawaii, California and Thailand

“Super blue-green algae” from Klamath Lake, OregonAphanizomenon flos-aquae: rich in essential amino

acids

Products made with Cyanobacteria

Diatoms

Phylum Bacillariophyta (a marine plankton)Symmetry options bilateral (pennate) vs radial

(centric)Two halves or “valves” fit together like a

pillboxCell walls and other parts made of silica

Silicon is 2nd most abundant element in Earth’s crust

Economically important as the producer of diatomaceous earth as filters, abrasives, insulators, pesticides, absorbants, etc.

Examples include: Cyclotella and NaviculaSometimes used for testing fine focus of

microscopes

Diatoms

DinoflagellatesBrown AlgaeRed AlgaeMore of everything else..

Next day…

Dinoflagellates

Phylum Dinophyceae of the Superphylum Alveolates

An “algal protist” that is mobile with two flagella1 equatorial and 1 in an apical groove

Unique apical horn opposite multiple antapical horns

Over 2000 species, mostly marine and parasiticSpecial (exterior) plate protection called thecaOnly eukaryote with permanent condensed

chromosomeExamples: Ceratium and Zooxanthellae

(endosymbiotic)Bio-luminescent cells glow when aggetatedCause red tides by producing neurotoxin

Leads to paralytic shellfish poisoning

Dinoflagellates

Seaweeds are marine algae!They evolved a variety of body types:

Filamentous: branched or unbranched chain of cells

Parenchymatous: cell divisions occur in 2D or 3D to produce tissue of randomly arranged cells

Pseudoparenchymatous: forming tissues that are characteristic of organ systems (complex parts)Thallus (brown algal tissue) is actually a tangle of

filaments

Seaweed or Algae?

Class Phaeophyceae (Brown Algae)

Class Phaeophyceae (Brown Algae)

2000 species that dominate rocky shorelinesi.e. Macrocytis (100m giant kelp), Fucus & SargassumAutotrophic (self-nourishment with inorganic materialContains chlorophyll a & c, with 4 membranes around

the chloroplastsCrazy fact: motile reproductive cells with dual flagella!A carotenoid pigment (fucoxanthin) for brown colourSome use root-like holdfast, stipe, blade or air bladdersOften grow on other plants, as epiphytesEaten by humans, herbivorous fish & gastropodsUsed as filler and stabilizers in products such as ice cream

and toothpaste. Also produces the gum-like algin, which is capable of absorbing 200-300 times its own weight!

Class Phaeophyceae (Brown Algae)

Phylum Rhodophyta (Red Algae)

Phylum Rhodophyta (Red Algae)

Life Cycle is Complex!

After fertilization…• Carposporophyte (2n) that

produces asexual carpospores (seed-like)

• Tetrasporophytes (2n) grow out to produce haploid tetraspores through meiosis

• Gametophytes (1n) grow on separate organisms to produce gametes (like pollen )

• Spermatia (non-motile sperm)

• Trichogyne (ovary-like)

About 6000 marine species – extremely diverseNon-motile (without flagella) – more plant-likeContains chlorophyll a, stores food as floridean starchThe red pigment comes from (pink) phycobiliproteinsMostly macroscopic with cellulosic cell walls, covered

by agar, & concentrates calcium carbonateToxic terpenoids to prevent herbivoryUsed for anti-cancer drugs, making yogurt and Nori

for sushiCoralline algae is hard like corals

Should we rename them as “Coralgal reefs”?

Phylum Rhodophyta (Red Algae)

From the order of your invasive species presentationChoose an algae (from #1-45) on the poster

Research this local species (use at least 3 resources)Prepare a ½ page report and ½ page labeled diagramInclude: Taxonomic Classification

Morphology / Anatomy, Morphogenesis / GrowthLife History / Life Cycle, Communities / Ecosystems Interactions / Symbiosis, Photosynthesis, Nutrient-

UptakeTemperature & salinity effects, Mobility, Pollution effectsPotential cultivation & grocery store botany

Your next research and report…

http://www.algaebase.org/

http://tolweb.org/tree/

http://biodiversity.bc.ca/

http://www.beatymuseum.ubc.ca/

http://scholar.google.ca/

Potential resources