Chapter 12 Eukaryotic Microorganisms, Helminths, and Arthropod Vectors

Fungi General characteristics heterotrophic nonphototrophic absorptive saprophytic decompose to obtain nutrients some pathogens

Fungi Morphology interconnected branched filaments Hyphae Mycelium individual filaments Mycelium connected hyphae coenocytic--undivided septa--incomplete divisions

Fungi Thallus body of the fungus Yeasts Molds Dimorphic Fleshy fungi single cells, oval shaped Molds mycelium Dimorphic stages of both yeast and mold Fleshy fungi fruiting structures mushrooms Figure 12.2

Fungi Reproduction Classification based on reproduction Assexual elongation and fragmentation budding division of cells asexual spores sporangiospores conidiospores Sexual spores sexual fusion of gametes

Fungi Lower Fungi Coenocytic Five classes Figure 12.5 Chytridiomycetes Water molds Gametes motility by flagella Oomycetes Nonmotile sexual spores Zygomycetes Terrestrial molds Disease: zygomycoses Figure 12.5

Fungi Higher Fungi septate hyphae Ascomycetes Basidiomycetes ascospores Basidiomycetes basidiospores mushrooms Deuteromycetes no sexual spores Penicillium Figure 12.6

Figure 12.6

Fungi and Plants Plant diseases Lower fungi Higher fungi Control Pythium spp.--Damping off Phytophthora infestans--Potato tuber slime Phytophthora ramorum--Sudden oak death Higher fungi Many diseases Apple scab, corn smut, Dutch elm disease Control Anti-fungal sprays Fungus-resistant plants

Fungi and Humans Human disease Mycoses Toxins Most often acquired from nature Treatment is difficult Toxins Muscarin Amanita muscaria mushroom Phalloidin and amanitin A. phalloides mushroom Ergot Claviceps purpurea—mold on rye Aflatoxin Aspergillus spp. Black mold toxin (sick building syndrome) Stachybotrys chartarum

Algae Aquatic Terrestrial Endophytic Varied environments Commercial freshwater marine Terrestrial moist soil tree bark surface of rocks Endophytic live in other organisms Varied environments Commercial Carageenan thickener Agar Alginic acid Food protein supplement animal food

Algae Classification Six groups Euglenoids Dinoflagellates Diatoms form of thalli wall structure pigments Euglenoids Dinoflagellates Diatoms Green algae Brown algae Red algae Figure 12.12

Lichens Mutualistic association fungus phototroph algae cyanobacteria Figure 12.13

Protozoa Four groups Flagellate Amoeboid Sporozoa Ciliate based on motility Flagellate Mastigophora Amoeboid Sarcodina pseudopods Sporozoa nonmotile Ciliate cilia Figure 12.14

Slime molds Not fungi Two groups True slime molds Cellular slime molds Slimy, veined mass Multinucleated cytoplasm Cellular slime molds Cells resemble amoeboid protozoa Dictyostelium discoideum Morphological changes in life cycle

Relatedness of Eukaryotes Figure 12.19

Helminths Flatworms Roundworms tapeworms flukes nematodes Figure 12.20 scolex attachment hooks/sucker germinal center new segments proglottids segments flukes Roundworms nematodes Figure 12.20

Life Cycle of Beef Tapeworm Figure 12.21

Arthropod Vectors Reservoir of infection mechanical vector external transmission not essential link biological vector part of life cycle internal transmission Figure 12.23