Chapter 12 Chapter 12

PowerPoint ® Lecture Slides for MICROBIOLOGY ROBERT W. BAUMAN Chapter 12 Characterizing and Classifying Eukaryotes

Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Eukaryotes • Major groups • Protozoa • ______• Algae • Slime Molds (& water molds) • Helminthes • Include both human pathogens and organisms vital for human life

Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Reproduction in Eukaryotes • More complicated than that in prokaryotes • Why? • More DNA – • Eukaryotic DNA packaged with histones as chromosomes in the nucleus • Nuclear ______

Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Nuclear Division • Nucleus has one or two complete copies of genome • Two types • Mitosis – division into two equal nuclei • (1) 2N (2) 2N • ______– nuclear division in which chromatids are separated • (1) 2N (4) 1N

• Mitosis • Meiosis I • Prophase • Prophase I • Metaphase • Metaphase I • Anaphase • Anaphase I • Telophase • Telophase I • Meiosis II • Prophase II • Metaphase II • Anaphase II • Telophase II Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Nuclear Division

• Typically occurs simultaneously with ______of mitosis

• ______in some algae and fungi, • Results in coenocytes

• Eukaryotic • Unicellular • Lack cell walls • ______• Usually ______• How? • Nutrition • Chemoheterotrophs - most • ______- a few

Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.16 Protozoa • Vegetative form • trophozoite • Asexual reproduction • fission • ______• or schizogony • Sexual reproduction • conjugation • Some produce cysts

Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Distribution of Protozoa • Require moist environments • Most live worldwide • in ponds, streams, lakes, and oceans • part of the plankton

• Very few are pathogens

• No mitochondria • Multiple flagella • Giardia lamblia • Trichomonas vaginalis (no cyst stage)

• Move by ______• Entamoeba • Acanthamoeba

• Nonmotile • ______• Complex ______• Plasmodium • Babesia • Cryptosporidium • Cyclospora

Sporozoites 1Infected mosquito bites 2 Sporozoites in salivary human; sporozoites undergo gland migrate through schizogony in bloodstream to liver cell; liver of human merozoites are produced 9 Resulting sporozoites migrate to salivary glands of mosquito 3 Merozoites Sexual released into reproduction bloodsteam from liver may infect Asexual new red blood 8 In mosquito’s cells Zygote digestive tract, reproduction gametocytes Intermediate host Female unite to form gametocyte zygote 4 Merozoite develops Male into ring stage in red gametocyte blood cell Ring 5 Ring stage stage grows and Definitive host divides, producing Another mosquito bites Merozoites are released 7 6 merozoites infected humnan and when red blood cell ingests gametocytes ruptures; some merozoites infect new red blood cells, and some develop into male and female gametocytes Merozoites

• Move by _____ • Complex cells • Paramecium • Balantidium coli is the only human parasite

• Move by ______• Photoautotrophs - Euglenoids • Chemoheterotrophs • Naegleria • Flagellated and amoeboid forms, meningoencephalitis • Trypanosoma • Leishmania

• Dinoflagellates • Cellulose in plasma membrane • Unicellular • Chlorophyll a and c, carotene, xanthins • Store starch • Some are symbionts in marine animals • Neurotoxins cause paralytic shellfish poisoning Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.14 Other protozoans

Radiolaria

Foraminifera

Figure 12.6 Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Reproduction in Protozoa • Most reproduction - asexual only • binary fission or ______• A few also use sexual reproduction • ______• Gametocytes that fuse to form diploid zygote • Some have _____ nuclei • Macronucleus - many copies of genome • controls ______, growth, and sexual reproduction • Micronucleus – involved in genetic recombination, sexual reproduction, and regeneration of ______Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Conjugation in Paramecium

Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Fungi • Aerobic or facultatively anaerobic • Chemoheterotrophic • Most are ______(nutrient recycling) • Cell walls composed of chitin • Lack chlorophyll; do not perform ______• ______antibiotics • Can spoil fruit, pickles, jams, and jellies • 30% cause diseases of ______, animals, and humans • Mycology is the study of fungi

•Acquire nutrients by absorption •Most are saprobes •Some trap and kill microscopic soil-dwelling nematodes

• ______• The fungal thallus consists of hyphae • A mass of hyphae is a mycelium.

• Unicellular fungi • Fission yeasts divide symmetrically • Budding yeasts divide ______

• Pathogenic dimorphic fungi • yeastlike at 37°C • moldlike at __°C

• Asexual reproduction – occurs in all fungus • mitosis and cytokinesis • Budding • Pseudohypha - series of buds that remain attached • Asexual spores • Sexual reproduction – most but not all • Zygote gives rise to ______

Asexual Spores of Molds

• ______• Conidiospore • Arthrospore • Blastoconidium • Chlamydospore

• Meiosis Diploid nucleus produces haploid nuclei (sexual spores) • Plasmogamy Haploid donor cell nucleus (+) penetrates ______of recipient cell ( –) • Karyogamy + and – nuclei fuse

• Sexual Spores

• Conjugation fungi • Coenocytic • Produce sporangiospores and ______. • Rhizopus, Mucor (Opportunistic, systemic mycoses)

• Zygospore Fusion of haploid cells produces one zygospore

• Sac fungi • Septate • Produce ascospores and frequently ______. • Aspergillus (opportunistic, systemic mycosis) • Blastomyces dermatitidis, Histoplasma capsulatum (systemic mycoses) • Microsporum, Trichophyton (cutaneous mycoses)

• Ascospore Formed in a sac (ascus)

• Club fungi • Septate • Produce basidiospores and sometimes conidiospores. • Cryptococcus neoformans (systematic mycosis)

• Basidiospore Formed externally on a pedestal (basidium)

• Contains heterogeneous collection of fungi who sexual stages are unknown • rRNA sequencing places most in Ascomycota, a few are Basidiomycota • Penicillium • Sporothrix (subcutaneous mycosis) • Stachybotrys, Coccidioides, Pneumocystis (systemic mycoses) • Candida albicans (Cutaneous mycoses)

Fungi Positive Effects Negative Effects Saccharomyces Bread, wine, beer Food spoilage

Trichoderma Cellulose used for juices and Cryphonectria fabric parasitica (chestnut blight) Taxomyces Taxol production Ceratocystis ulm (Dutch elm disease)

Entomorphaga Gypsy moth control

• Systemic mycoses Deep within body • Subcutaneous mycoses Beneath the skin • Cutaneous mycoses Affect hair, skin, nails • Superficial mycoses Localized (eg. hair shafts) • Opportunistic mycoses Caused by normal microbiota or fungi that are normally

Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Lichens • Mutualistic combination • Green alga (or cyanobacterium) & fungus • Alga produces and secretes carbohydrates • Fungus provides holdfast • Abundant throughout the world • Grow on soil, rocks, leaves, tree bark, • other lichens, ______• Important in creation of soil from rocks • Eaten by many animals

•Eukaryotic •Unicellular, filamentous, or multicellular (thallic) •Most are photoautotrophs

• Brown algae (kelp) • Cellulose + alginic acid cell walls • Multicellular • Chlorophyll a and c, xanthophylls • Store carbohydrates • Harvested for algin

• Red algae • Cellulose cell walls • Most multicellular • Chlorophyll a and d, phycobiliproteins • Store glucose polymer • Harvested for agar and carrageenan

• Green algae • Cellulose cell walls • Unicellular or multicellular • Chlorophyll a and b • Store glucose polymer • Gave rise to plants

• Diatoms • Pectin and silica cell walls • Unicellular • Chlorophyll a and c, carotene, xanthophylls • Store oil • Fossilized diatoms formed oil

Figure 12.28 Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Dinoflagellata • Dinoflagellates • Cellulose in plasma membrane • Unicellular • Chlorophyll a and c, carotene, xanthins • Store starch • Some are symbionts in marine animals • Neurotoxins cause paralytic shellfish poisoning Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.14 Oomycota • Water molds • Cellulose cell walls • Multicellular • Chemoheterotrophic • Produce zoospores • Decomposers and plant parasites • Phytophthora infestans responsible for Irish potato blight • P. cinnamomi infects Eucalyptus • P. ramorum causes sudden oak death

• Cellular slime molds • Plasmodial slime molds • Resemble amoebas, • Multinucleated large ingest bacteria by cells phagocytosis • Cytoplasm separates • Cells aggregate into into stalked sporangia stalked fruiting body. • Nuclei undergo meiosis • Some cells become and form uninucleate spores haploid spores Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Helminths • Normal Helminths – • Free living • Kingdom: Animalia • Soil or water • Phylum: Platyhelminthes • Decomposers (flatworms) • Parasitic worms • Class: Trematodes (flukes) • Multicellular animals • Class: Cestodes (tapeworms) • microscopic diagnostic stages • Phylum: Nematodes (roundworms) • usually eggs or larvae • Dependent on host - Chemoheterotrophic

Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.29 Arthropods as Vectors • Vectors = animals that carry and transmit microscopic pathogens • Kingdom: Animalia • Phylum: Arthropoda (exoskeleton, jointed legs) • Class: Insecta (6 legs) • Lice, fleas, mosquitoes • Class: Arachnida (8 legs) • Mites and ticks • May transmit diseases Figure 12.31, 32 Copyright © 2004 Pearson Education,(vectors) Inc. publishing as Benjamin Cummings Arthropods as Vectors