Download
cyanobacteria algae n.
Skip this Video
Loading SlideShow in 5 Seconds..
Cyanobacteria & Algae PowerPoint Presentation
Download Presentation
Cyanobacteria & Algae

Cyanobacteria & Algae

595 Vues Download Presentation
Télécharger la présentation

Cyanobacteria & Algae

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Cyanobacteria & Algae

  2. Cyanobacteria

  3. ~3,500 mya cyanobacteria evolved

  4. Stromatolites • Stromatolites are produced when colonies of cyanobacteria bind calcium–rich sediments.

  5. Stromatolites • Cyanobacteria have an abundant fossil record, evidence that cyanobacteria was prevalent throughout this time period

  6. Stromatolites

  7. Early Earth’s Atmosphere

  8. Cyanobacteria • Earth’s early atmosphere practically devoid of free Oxygen. • Cyanobacteria first photosynthetic organism to evolve (~3,500 mya) on earth • Cyanobacteria played the decisive role in elevating the level of oxygen in the atmosphere of early Earth, staging it for the arrival of life as we know it on this planet! HOORAY FOR CYANOBACTERIA!

  9. Cyanobacteria • Earth’s early atmosphere practically devoid of free Oxygen. • Cyanobacteria first photosynthetic organism to evolve (~3,500 mya) on earth • Cyanobacteria played the decisive role in elevating the level of oxygen in the atmosphere of early Earth, staging it for the arrival of life as we know it on this planet! HOORAY FOR CYANOBACTERIA!

  10. FIRST POLLUTION CRISIS! ~3,500 mya cyanobacteria evolved

  11. Oscillatoria • Filamentous Cyanobacteria • The cells are usually joined only by their walls or mucilaginous sheaths. • Each cell leads an independent life.

  12. Nostocfilamentous cyanobacteria in a ball!Freshwater habitats

  13. Many Cyanobacteria fix nitrogen • Plants (and other organisms) need nitrogen for survival. • Nitrogen gas, in the atmosphere, is not in form plants can take up. • Many cyanobacteria can convert the nitrogen gas to ammonium, a useable form of nitrogen! (“Nitrogen fixation”)

  14. Anabaena • Rice can often be grown continuously on the same land without the addition of fertilizers because of the presence of nitrogen-fixing cyanobacteria, such as Anabaena, in the rice paddies.

  15. Algae Phycology: the study of algae

  16. Phylum Dinophyta: the Dinoflagellates • Closely related to some protozoa (“animal-like protists). • 2000-4000 species known • Found in marine and freshwater habitats (most are marine)

  17. Phylum Dinophyta: the Dinoflagellates • Most are unicellular biflagellates • Flagella beat in two grooves, causing whirling-forward motion • Greek word dinos: ‘whirling’ • Latin flagellum: diminutive term for whip

  18. Theca: stiff cellulose plates “coat of armor” (Gonyaulaxpolyedra)

  19. Not all Dinoflagellates have theca Bioluminescent marine dinoflagellate (Noctilucascintillans)

  20. Dinoflagellate nutrition • Only about half of all dinoflagellate species are photosynthetic. • Non-photosynthetic dinoflagellates (and some photosynthetic dinoflags) obtain nutrition either by ingesting solid food particles or by absorbing dissolved organic compounds.

  21. Dinoflagellate nutrition • 20% produce highly toxic compounds • Pfiesteriapiscicida produce a toxic substance that paralyzes the fishes’ respiratory systems, and then feeds on the fish.

  22. Symbiosis with Dinoflagellates • Symbiotic relationship with sponges, jellyfish, sea anemones, corals, octopuses and squids, snails, etc…) • In coral polyps, the dinoflagellates produce glycerol, which is used for coral respiration • The coral produces amino acids for the dinoflagellates

  23. Bioluminescent Dinoflagellates • When disturbed (by a wave, or other physical aggitation), some dinoflagellates produce bioluminescent compounds • Thought to serve as protection against predators by startling them.

  24. Phylum Euglenophyta (Euglenoids) • 900 known species • Habitat: mostly freshwater, some marine • About 1/3 of the genera in the phylum are photosynthetic. • Euglenoides are flagellated and unicellular (except for one colonial genus)

  25. Phylum Bacillariophyta (Diatoms) • Over 100,000 living species • Habitat: Marine & Freshwater • Unicellular of colonial, lack flagella • Important components of the phytoplankton, a primary source of food for marine and freshwater aquatic animals. • Provide carbohydrates, fatty acids, and vitamins to animals

  26. Phylum Bacillariophyta (Diatoms) • Unique structure of two-part cell walls, that overlap each other like a petri dish. • Each part is called a frustule and is made of silica. • Species distinguished by frustule ornamentation.

  27. Phylum Bacillariophyta (Diatoms) • Diatomaceous earth (DE): fine, crumbly, yet abrasive substance made from silica frustules of diatoms that have accumulated in ocean sediments over millions of years. • Used as silver polish, filtering material, natural insecticide, used in cosmetics, used to rid intestinal worms and parasites from animals and humans, used as an insulating material.

  28. Phylum Chrysophyta (Chrysophytes) • About 1000 species • Habitat: Mainly freshwater, few marine • Unicellular or colonial, flagella • Many have characteristic gold color (Greek chrysos, “gold,” and phyton, “plant”) • i.e. Dinobryon, a colony of single cells living in tubes. Each cell can consume 36 bacteria/hour. • Major consumer of bacteria in cooler North American lakes

  29. Phylum Phaeophyta (Brown Algae) • About 1500 species, most multicellular • Almost entirely marine • Dominate rocky shores in cool climates • Range in size to microscopic (Ectocarpus) to as much as 195 feet and 650 lbs (kelp)! • Greek: phaeo, “dark-colored”

  30. Kelps and Rockweed Laminaria sp. Holdfast Fucus sp.

  31. Fucus sp.

  32. Phylum Phaeophyta (Brown Algae) • Algin: mucilaginous material used economically as a stabilizer and emulsifier for some foods and for paint, and as coating for paper • In the cell, algin provides flexibility and toughness to allow the algae to withstand stress from waves • Also helps prevent drying when the algae are exposed during low tides.

  33. Phylum Rhodophyta (Red Aglae) • 4000-6000 species, mostly multicelluar • Habitat: Mainly marine, about 100 freshwater • Many tropical species, many found in coral reefs

  34. Phylum Rhodophyta (Red Aglae) • Carageenan: gelatinous extracts from red algae (i.e. Chondrus crispus) • Used as food additives for hundreds of years. • Used in Products such as ice cream, pudding, condensed milk, toothpaste, shampoo, soy milk, artificial Alien saliva.

  35. Phylum Chlorophyta (Green Algae) • 17,000 species (multicellular and unicellular) • Habitat: Marine and Freshwater, some terrestrial (in the soil, in snow, on tree trunks…), some living symbiotically with other organisms.

  36. Closest relatives to plants • Class Charophyceae within the phylum Chlorophyta (green algae) includes members that most closely resemble true plants. • Bryophytes (mosses, etc.) probably derived from an extinct member of Charophyceae Class. • The Order Charales possess traits found otherwise only in true plants (i.e. mosses and vascular plants).

  37. Chara (class Charophyceae) • Chara aka “stonewort” (Class Charophyceae) grows in shallow waters of temperate lakes. • Very closely related to true plants as evidenced by DNA analysis and several other characteristics • Branched growth • Retention of egg • Sperm morphology • Numerous chloroplasts per cell Chara sperm Moss sperm

  38. We Love Algae