Classification of Protista Fungi Kingdom Protista This kingdom

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Classification of Protista & Fungi

Classification of Protista & Fungi

Kingdom Protista • This kingdom is in the Eukarya Domain • Little is known

Kingdom Protista • This kingdom is in the Eukarya Domain • Little is known of the evolutionary relationships of its members • Similar features are just as likely to be due to convergent evolution as they are due to recent common ancestry • Protists can be algae/plant-like, animal-like, fungus-like, unicellular, or occasionally multicellular

Algae-Like Protists (or Plant-Like) • Autotrophic; obtain energy via photosynthesis • 1. Euglenophyta (euglenoids)

Algae-Like Protists (or Plant-Like) • Autotrophic; obtain energy via photosynthesis • 1. Euglenophyta (euglenoids) – 1 -3 Flagella – Can become heterotrophic in darkness – Eyespot: phototaxis • 2. Dinoflagellata (dinoflagellates) – 2 Flagella – Some bioluminescent – Some produce nerve toxins which accumulate in shellfish & can cause illness

Algae-Like Protists (or Plant-Like) • 3. Chrysophyta (golden algae) – 2 Flagella – Golden

Algae-Like Protists (or Plant-Like) • 3. Chrysophyta (golden algae) – 2 Flagella – Golden or Yellow • 4. Bacillariophyta (diatoms) – Have tests (shells) with silica (Si. O 2) • 5. Chlorophyta (green algae) – – – Contain chlorophyll a and b Cellulose cell walls Various gamete types Form colonies (some large – volvox) Ancestors of plants?

Algae-Like Protists (or Plant-Like) • 6. Phaeophyta (brown algae) – Multicellular – Flagellated sperm

Algae-Like Protists (or Plant-Like) • 6. Phaeophyta (brown algae) – Multicellular – Flagellated sperm cells – Seaweeds, Kelps • 7. Rhodophyta (red algae) – Red accessory pigments (phycobilins) – Multicellular – Gametes have no flagella

Animal-Like Protists (Protozoa) • Heterotrophic; get energy from living things or dead organic matter

Animal-Like Protists (Protozoa) • Heterotrophic; get energy from living things or dead organic matter • 1. Rhizopoda (Amoebas) – Move by extensions of the body called pseudopodia (also encircles food and absorbs via phagocytosis) • 2. Foraminifera (Forams) – Have tests usually made of calcium carbonate – Ancient marine deposits rich in certain foram tests are good indicators of underlying oil deposits

Animal-Like Protists (Protozoa) • 3. Zoomastigophora (zooflagellates) – Some mutualistically digest cellulose in the

Animal-Like Protists (Protozoa) • 3. Zoomastigophora (zooflagellates) – Some mutualistically digest cellulose in the guts of termites – Others are parasites: Trypanosoma is one transmitted by tsetse flies and causes African sleeping sickness • 4. Sporozoa – Parasites of animals – No physical means of motility – Form spores that can be dispersed and live parts of their life cycle in animals (malaria, for example)

Animal-Like Protists (Protozoa) • 5. Ciliophora – Distinguished by their cilia, for motion –

Animal-Like Protists (Protozoa) • 5. Ciliophora – Distinguished by their cilia, for motion – Specialized structures like mouths, anal pores, contractile vacuoles (water balance)

Fungus-Like Protists • Resemble fungi because they form either filaments or spore-bearing bodies similar

Fungus-Like Protists • Resemble fungi because they form either filaments or spore-bearing bodies similar to the fungi • 1. Acrasiomycota (cellular slime molds) – Exhibit both fungus-like and animal-like characteristics during their life cycle – Spores germinate to amoebas which feed on bacteria – When food gone, they aggregate to one unit and migrate as a slug – Cells then form stalks with a spore bearing capsule on top similar to fungi

Fungus-Like Protists • 2. Myxomycota (plasmodial slime molds) – Grow as a single spreading

Fungus-Like Protists • 2. Myxomycota (plasmodial slime molds) – Grow as a single spreading mass (plasmodium) feeding on decaying veg. – When environment dessicates, stalks bearing spore capsules form – Haploid spores released from the capsule germinate into haploid amoeboid or flagellated cells, which fuse to form a diploid cell – The diploid cell grows into a spreading plasmodium

Fungus-Like Protists • 3. Oomycota – Water molds, downy mildews, and white rusts –

Fungus-Like Protists • 3. Oomycota – Water molds, downy mildews, and white rusts – Parasites or Saprobes – Form filaments (hyphae) which secrete enzymes that digest surrounding substances for absorption and digestion – Multinucleated cells – Cell walls made of cellulose, rather than the chitin found in true fungi

Kingdom Fungi • Grow as filaments called hyphae • A mass of hyphae is

Kingdom Fungi • Grow as filaments called hyphae • A mass of hyphae is called mycelium • Some fungi have septa (cross walls), which divide the filament into compartments containing a single nucleus • When the lack septa, they are called coenocytic (multinucleated) • Cell walls consist of chitin (nitrogencontaining polysaccharide)

Kingdom Fungi • Either parasites or saprobes, absorbing the breakdown products from the action

Kingdom Fungi • Either parasites or saprobes, absorbing the breakdown products from the action of digestive enzymes they secrete • Many parasitic fungi have hyphae called haustoria that penetrate their host for nutrient absorption

Fungi Sex • Mostly haploid, but most form temporary diploid structures for sexual reproduction…

Fungi Sex • Mostly haploid, but most form temporary diploid structures for sexual reproduction… stages: – 1. Plasmogamy – fusing cells from two different fungal strains to produce a single cell with nuclei from both strains. Pair of haploid nuclei (1 from each strain) is called a dikaryon. – 2. Karyogamy – fusing of the two haploid nuclei of a dikaryon to form a single diploid nucleus. – 3. Meiosis – the diploid nucleus restores haploid condition. Daughter cells develop into haploid spores, which germinate and form haploid hyphae.

Fungi Asexual Reproduction • Various means: – Fragmentation: breaking up of hyphae – Budding:

Fungi Asexual Reproduction • Various means: – Fragmentation: breaking up of hyphae – Budding: pinching off of small hyphal outgrowth – Asexual spores: • Sporangiospores – produced in saclike capsules called sporangia that are borne on a stalk called a sporangiophore • Conidia – formed at the tips of specialized hyphae, not enclosed inside sacs. Hyphae bearing conidia are called conidiophores

Fungus Groups • 1. Zygomycota – Lack septa – Reproduce sexually by fusion of

Fungus Groups • 1. Zygomycota – Lack septa – Reproduce sexually by fusion of hyphae from different strains – Example: Bread Mold • 2. Ascomycota – Have septa – Reproduce sexually by producing 8 haploid ascospores in a sac called an ascus – Examples: yeasts, powdery mildews, truffles

Fungus Groups • 3. Basidiomycota – Have septa – Reproduce sexually by producing haploid

Fungus Groups • 3. Basidiomycota – Have septa – Reproduce sexually by producing haploid basidiospores – Fruiting body: basidiocarp (mushroom) • 4. Deuteromycota (imperfect fungi) – No sexual reproductive cycle has been observed – Example: Penicillium

Fungus Groups • 5. Lichens – Mutualistic associations between fungi and algae – Algae

Fungus Groups • 5. Lichens – Mutualistic associations between fungi and algae – Algae provides sugar from photosynthesis, sometimes N – Fungus provides water and protection from the environment, sometimes shield algae from UV radiation, excess light, or even toxic substances for discouraging grazers

Fungus Groups • 6. Mycorrhizae – Mutualistic associations between fungi and roots of plants

Fungus Groups • 6. Mycorrhizae – Mutualistic associations between fungi and roots of plants – Plant provides sugars to the fungus – Fungus increases the ability of the roots to absorb water and minerals, especially phosphorus