Diversity

1. Diversity • 2.7 billion years ago, microbes invented photosynthesis • Water split to get H needed to turn CO2 into sugars, O2 left behind • All the iron on the surface rusted • Oxygen accumulated • Organisms adapted to new world • They could get bigger; more efficient metabolism

2. Eukaryotes • Bigger, more complicated cells than prokaryotes • Multicellular organisms developed • Four kingdoms of eukaryotes currently recognized.

3. Fungi, the champion decomposers • Familiar terms: what do they mean exactly? • Molds: types of fungi that grow as long threads or filaments. • When they reproduce, they look different. • Yeasts: another way fungi can look; oval, unicellular in appearance. • Some fungi can grow as yeasts or molds. • Mushrooms: these are reproductive structures of certain types of fungi.

4. How do Fungi grow? • Fungi are heterotrophs • They are the great decomposers, break down all kinds of polymers. Can destroy wood, rubber, paint, all types of things. • They are never photosynthetic! • Fungi grow into, through their food. • They release enzymes that break things down • They take up resulting small molecules • They grow at the tips and penetrate.

5. Fungi and plants • Some fungi are parasites • Many plant diseases are caused by fungi • Fusarium, for example • Many fungi grow along with plants • Myco (fungi) rrhizae (roots) = mycorrhizae • Fungi growing with plant roots help furnish the plant with minerals from the soil • Plants leak nutrients to feed fungi • Both prosper

6. Fungi and humans • As decomposers, important in ecosystem • Industrial problems • Some cause disease • Athlete’s foot, yeast infections, histoplasmosis • Serious infections with diseases like AIDS • Source of important antibiotics • Penicillium is a fungus • Important in food and other industries • Citric acid, soy sauce, cheeses, mushrooms

7. How are they classified? • Once again, it’s about sex. • Three main types of fungi • When two different mating types get together, they make sexual spores • The type of structure the spores are found in determines the type of fungus • Mushroom is a type of spore-bearing structure • Fungi also reproduce asexually too • They make lots of spores this way, but not involved in classification

8. Sexual reproductive structures that Fungi make

9. Protista: one kingdom, or 8? • The Protists are unicellular eukaryotes • For “pond scum” they show incredible diversity • Protists were always lumped together by what they aren’t. • New schemes suggest grouping them into 8 or more different KINGDOMS • As different from each other as they are from plants and animals.

10. Is there an easy way to learn about the Protists? • Here’s one. Divide them into 3 groups: • Plant-like • Animal-like • Fungus-like

11. Plant-like Protists • Contain chloroplasts • Representatives • Diatoms (right). • Diatomaceous earth = fossilized diatoms: abrasives and slug repellants. • Red, brown, yellow algae • Seaweed, source of agar • Dinoflagellates • Neurotoxins and red tide http://www.bhikku.net/archives/03/img/diatoms.JPG www.enviroliteracy.org/ article.php/534.html

12. Animal-like protists • Capable of ingesting their food. • Capable of moving around • Amoebas • Protozoa with flagella or cilia • Disease-causing protists belong to this group • Diarrhea, malaria, STD http://en.wikipedia.org/wiki/Slime_mold http://ar.geocities.com/seti_argentina/estamos_solos/ameba.jpg

13. Fungus-like • Water molds • Motile by flagella (fungi aren’t.) • Phytophora infestans, cause of Irish potato blight • Slime molds • “the blob”, one giant cell or groups of cells that crawl over the ground • Digest everything in their path res2.agr.ca/lethbridge/ emia/SEMproj/phyinf_f.htm http://en.wikipedia.org/wiki/Slime_mold

14. The Kingdom Plantae • Plants are highly successful • Photosynthetic, use sunlight energy and carbon dioxide • Also need minerals to grow

15. The world of Plants • The most abundant and successful type of plant are flowering plants, the Angiosperms. • There’s actually 9 other completely different types of plants. • Mosses • Ferns • Cycads • Conifers (most evergreens w/ needles) • 6 others

16. Examples: most primitive to most advanced • Mosses • Have no roots • No seeds • Ferns • Produce spores, not seeds • Gymnosperms • Naked seeds, in cones • Angiosperms • Flowers and seeds

17. Pictures cited • http://www.mpm.edu/collect/fern-6.gif www.maxwaugh.com/ arb02/moss.html http://www.huntergardens.org.au/images/conifer1.jpg www.sbs.utexas.edu

18. What have angiosperms got that makes them good? • Specialized structures for pulling water out of dry ground: roots • Specialized structures for exchanging gases with the atmosphere and collecting sunlight: leaves • Structures for holding the leaves up where they can do these things: shoots

19. Flowers • Attract pollinators that spread male gametes (pollen, from anthers) to female gametes (inside ovaries) • Provide a protective place for embryo (within seeds) to form. • Seeds are within or attached to fruit. • Fruit is a mechanism for dispersal of seed • Some is eaten and excreted elsewhere • Some sticks and is carried about • Some blow, some float, many strategies