Chapter 12 Eukaryotes 2 slide PDF

3/6/2021 Chapter 12 The Eukaryotes: Fungi Algae Prot...

3/6/2021 Chapter 12 The Eukaryotes: Fungi Algae Protozoa Helminths Arthropods Overview of Eukaryotic Reproduction DNA packaged as chromosomes in the nucleus Have variety of methods of asexual reproduction Many reproduce sexually by forming gametes and zygotes Algae, fungi, and some protozoa reproduce both sexually and asexually Consists of nuclear and cytoplasmic division Nuclear division has one or two complete copies of genome Single copy (haploid) ‐ Most fungi, many algae, some protozoa Two copies (diploid) ‐ Remaining fungi, algae, and protozoa – Types Mitosis Meiosis 1  3/6/2021 Cytokinesis – cytoplasmic division Figure 12.2 Different types of cytoplasmic division- overview 2  3/6/2021 Schizogony Produce multinucleate schizont After cytokinesis = many daughter cells Figure 12.3 Schizogony Fungi – Mycology Chemoheterotrophic (saprophytic) – Obtain food through absorption Cell wall contains chitin Lack chlorophyll Aerobic or facultative anaerobic Multicellular (molds), unicellular (yeasts) Sexual and asexual spores – Classified based on their form of sexual reproduction Cellular arrangement – unicellular, filamentous, fleshy 3  3/6/2021 Significance of Fungi Decompose dead organisms and recycle their nutrients Help plants absorb water and minerals Used for food and in manufacture of foods and beverages Produce antibiotics Serve as important research tools 30% cause diseases of plants, animals, and humans Can spoil fruit, pickles, jams, and jellies Fungal Morphology Thallus – the body of the mold or fleshy fungus – vegetative Consists of long filaments – hyphae (joined) together Mycelium. Septate Hyphae Coenocytic hyphae (aseptate) 4  3/6/2021 Fungal Morphology Pearson Education, 2010 Figure 12.2 Yeasts Unicellular fungi Fission yeasts – divide symmetrically – binary fission Budding yeasts – divide asymmetrically – budding Pseudohyphae – short chains formed when the buds do not completely separate Filamentous fungi produce lightweight spores that disperse over large distances 5  3/6/2021 Asexual Spores Asexual Spores 6  3/6/2021 Sexual Reproduction Three phases: – Plasmogamy: Haploid donor cell nucleus (+) penetrates cytoplasm of recipient cell (–) – Karyogamy: + and – nuclei fuse – Meiosis: Diploid nucleus produces haploid nuclei (sexual spores) 7  3/6/2021 Sexual Spores Zygospore: Fusion of haploid cells produces one zygospore Pearson, 2010 Figure 12.6 Sexual Spores Ascospore: Formed in a sac (ascus) Pearson, 2010 Figure 12.7 8  3/6/2021 Sexual Spores Basidiospore: Formed externally on a pedestal (basidium) Pearson, 2010 Figure 12.6 Fungal Divisions Zygomycota Ascomycota Basidiomycota Deuteromycetes 9  3/6/2021 Fungal Division: Zygomycota Conjugation fungi Sexual reproduction by zygospores Asexual reproduction by sporangiospores in a sporangium Coenocytic hyphae (no septa) Example – Rhizopus Rhizopus 10  3/6/2021 Fungal Division: Ascomycota Sac fungi Septate hyphae Sexual reproduction by ascospores in ascus sac Asexual reproduction by conidiospores on conidia Fungal Division: Basidiomycota Figure 12.23 Basidiocarps (fruiting bodies) of the bird's nest fungus, Club fungi Crucibulum Septate hyphae Sexual reproduction by basidiospores on basidium pedestal Asexual reproduction by fragmentation Important genera – Coprinus – Amanita 11  3/6/2021 Economic Effects of Fungi Saccharomyces cerevisiae: Bread, wine, HBV vaccine Trichoderma: Cellulase Taxomyces: Taxol Entomophaga: Biocontrol Paecilomyces: Kills termites Fungal Diseases (Mycoses) Systemic mycoses: Deep within body Subcutaneous mycoses: Beneath the skin – Occur by direct implantation of fungal spores or mycelium into a puncture of the skin Cutaneous mycoses: Affect hair, skin, and nails – Triggers immune response – Permanent damage to tissue Superficial mycoses: Localized, e.g., hair shafts – Does not penetrate living tissue – No immune response triggered Opportunistic mycoses: Caused by normal microbiota or environmental fungi 12  3/6/2021 Superficial mycoses Piedra ‐ Black Piedra Malassezia furfur – Pityriasis Ascomycota Basidiomycota Hyphae/spores on hair shaft Fungus interferes with Central & S. America, SE Asia melanin production Treat: shave or oral Treat: topical or oral terbinafine ketoconazole Cutaneous mycoses Dermatophytosis – ringworm and athlete’s foot Trichophyton, Microsporum, Epidermophyton Ascomycota Skin & nails, Trichophyton includes hair Treat: topical or oral terbinafine 13  3/6/2021 Cutaneous/Subcutaneous mycoses Sporothrix schenckii Ascomycota ‘rose gardener’s fever’ Mexico, Latin America, Africa & warm/moist US Treat: topical or oral terbinafine Subcutaneous mycoses Cladophialophora Acremonium Ascomycota Ascomycota Mycetoma Chromoblastomycosis Pus‐filled tumors, skin, fascia, bones Dry wart‐like scales of hands and feet Remove tissue Remove tissue /limb 14  3/6/2021 Systemic mycoses Cryptococcus neoformans Blastomyces dermatitidis Basidiomycota Meningitis Capsule Found in soil, bird feces IV amphotericin B & oral Ascomycota 5‐fluorocytosine Blastomycosis Mucor Zygomycota medicinenet.com dermnetnz.org 15  3/6/2021 Systemic mycoses Aspergillus niger Stachybotrys chartarum Ascomycota Ascomycota Systemic mycoses Coccidiodes immitis Lesion from lung infection Histoplasma capsulatum Ascomycota Ascomycota Asymptomatic Found in soil, bird/bat feces 5% clinical histoplasmosis Spreads to brain and spinal Treat: amphotericin B column 16  3/6/2021 Algae Simple eukaryote Unicellular, colonial, multicellular Photoautotrophs Food through diffusion Aquatic habitats Divisions by: – Pigments – Cell wall types – Food storage polymers Brown Algae – Phaeophyta (kelp) Cellulose and alginic acid cell walls Multicellular Store carbohydrates Harvested for algin 17  3/6/2021 Red Algae – Rhodophyta Cellulose cell walls Most are multicellular, delicately branched Store glucose polymer Harvested for agar Figure 12.28 Antithamnion, a red alga Green Algae – Chlorophyta Cellulose cell walls Unicellular or multicellular Store glucose polymer Gave rise to plants Pearson, 2010 Figure 12.11a 18  3/6/2021 Protozoa (Protists) Defined by 3 characteristics – Eukaryotic, Unicellular, lacks a cell wall Chemoheterotrophic Food by ingestion and absorption Motile by means of cilia, flagella, and/or pseudopodia (‐NOT Apicomplexans) Vegetative form is a trophozoite Asexual reproduction is by fission, budding, or schizogony Sexual reproduction by conjugation Some produce cysts in adverse conditions Distribution of Protozoans Require moist environments Most live in ponds, streams, lakes, and oceans Others live in moist soil, beach sand, and decaying organic matter Morphology of Protozoans 2 nuclei – Macronucleus, Micronucleus Mitochondria vary in numbers and kinds Contractile vacuoles 19  3/6/2021 Phylum Parabasala Lack mitochondria Trichonympha Single nucleus Parabasal body Numerous flagella Trichonympha Trichomonas vaginalis Trichomonas vaginalis www.sciencephoto.com Phylum Diplomonadida Lack mitochondria Lack Golgi bodies Lack peroxisomes Contain 2 equal‐sized nuclei Multiple flagella Giardi lamblia Pearson Education, 2010 20  3/6/2021 Phylum Euglenozoa Unicellular Rigid membrane, no cell wall Move by flagella Mitochondria with cristae Photoautotrophs Chloroplasts containing chlorophyll Reproduce by mitosis Form cysts in harsh conditions Phylum Euglenozoa ‐ Kinetoplastids Trypansoma brucei – African sleeping sickness – Glossina Tsetse fly – Spread among cattle, sheep, wild animals, humans – 3 infectious stages – Vector bite – Protozoans in blood – Invasion of nervous system https://www.youtube.com/watch?v=4aVUrGO97Zg 21  3/6/2021 Phylum Euglenozoa ‐ Kinetoplastids Trypanosoma cruzi – Chagas Disease – True bug (Triatoma) ‘kissing bugs’ – Bite = swelling = fatigue = fever = swollen lymph nodes that drain – Asymptomatic phase 10‐20 years = difficulty swallowing, severe constipation, irregular heartbeat, congestive heart failure = death Phylum Euglenozoa ‐ Kinetoplastids Leishmania – Disease of skin and oral mucous membrane – Cutaneous leishmaniasis – Mucocutaneous – Visceral http://animal.discovery.com/videos/monsters‐ inside‐me‐cutaneous‐leishmaniasis.html 22  3/6/2021 Phylum Alveolates ‐ Ciliates Move by cilia Chemoheterotrphs Balantidium coli Didinium ‐phagocytize other protozoa Phylum Alveolates ‐ Apicomplexans Chemoheterotrophic Cyclospora Nonmotile Intracellular parasite Complex life cycles Babesia cdc.gov Cryptosporidium Camlt.org cdc.gov 23  3/6/2021 Phylum Alveolates ‐ Apicomplexans Toxoplasma gondii Phylum Alveolates ‐ Apicomplexans Plasmodium vivax http://animal.discovery.com/videos/monsters‐inside‐me‐malaria‐parasite.html 24  3/6/2021 Phylum Alveolates ‐ Dinoflagellates Unicellular Photosynthetic pigments (green/orange) Cells contain cellulose (like algae) Food reserves are starch and oil Photoautotrophic Freshwater and marine plankton Many are motile with 2 flagella Many are bioluminescent Produce neurotoxins Phylum Alveolates ‐ Dinoflagellates Pfiesteria Gymnodinium Gonyaulax 25  3/6/2021 Phylum Amoebozoa Lobe‐shaped pseudopodia Lack shells Free‐living Naegleria fowleri Acanthamoeba Phylum Amoebozoa Entamoeba histolytica http://animal.discovery.com/videos/monsters‐inside‐me‐entamoeba‐histolytica.html 26  3/6/2021 Helminths – Flatworms & Roundworms Eukaryote, multicellular – Digestive, circulatory, nervous, excretory, and reproductive Chemoheterotrophic Parasitic lifestyles may: – Lack digestive system – Have reduced nervous system – Have reduced locomotion Complex reproductive lifestyle Egg larva(e) adult – Monoecious (hermaphroditic) – Dioecious – Separate male and female Kingdom: Animalia – Phylum: Platyhelminthes (flatworms) Class: Trematodes (flukes) Class: Cestodes (tapeworms) – Phylum: Nematoda (roundworms) Trematodes, or Flukes Schistosoma Clonorchis – Asian liver fluke 27  3/6/2021 Cestodes, or Tapeworms Scolex – head Proglottids – segmented body Monoecious Taenia saginata beef tapeworm Taenia solium – pork tapeworm Dipylidium caninum 28  3/6/2021 Nematodes – Roundworms Some infect humans as eggs Ascaris lumbricoides Enterobius – pinworm Trichinella spiralis – cause of trichinosis Sciencesource.com Necator americanus 29  3/6/2021 Dirofilaria immitis Arthropods as Vectors Mechanical transmission Biological transmission – Microbe multiplies in vector Definitive host – Microbe’s sexual reproduction in vector Figure 12.30 30 3/6/2021 31