© 2004 wadsworth – thomson learning chapter 12 eukaryotic microorganisms, helminths, and...
TRANSCRIPT
© 2004 Wadsworth – Thomson Learning
Chapter 12Chapter 12Eukaryotic Microorganisms, Eukaryotic Microorganisms, Helminths, and Arthropod Helminths, and Arthropod
VectorsVectors
© 2004 Wadsworth – Thomson Learning
Fungi
• General characteristics– heterotrophic– nonphototrophic– absorptive– saprophytic
• decompose to obtain nutrients• some pathogens
© 2004 Wadsworth – Thomson Learning
Fungi
• Morphology– interconnected branched filaments– Hyphae
• individual filaments
– Mycelium• connected hyphae• coenocytic--undivided• septa--incomplete divisions
© 2004 Wadsworth – Thomson Learning
Fungi
• Thallus– body of the fungus– Yeasts
• single cells, oval shaped
– Molds• mycelium
– Dimorphic• stages of both yeast and mold
– Fleshy fungi• fruiting structures• mushrooms
Figure 12.2
© 2004 Wadsworth – Thomson Learning
Fungi
• Reproduction– Classification based on reproduction– Assexual
• elongation and fragmentation• budding• division of cells• asexual spores
– sporangiospores– conidiospores
– Sexual• spores
– sexual fusion of gametes
© 2004 Wadsworth – Thomson Learning
Fungi
• Lower Fungi– Coenocytic– Five classes
• Chytridiomycetes– Water molds– Gametes motility by
flagella
• Oomycetes– Water molds– Nonmotile sexual
spores
• Zygomycetes– Terrestrial molds– Disease:
zygomycoses
Figure 12.5
© 2004 Wadsworth – Thomson Learning
Fungi
• Higher Fungi– septate hyphae– Ascomycetes
• ascospores
– Basidiomycetes• basidiospores• mushrooms
– Deuteromycetes• no sexual spores• Penicillium
Figure 12.6
© 2004 Wadsworth – Thomson Learning
Figure 12.6
© 2004 Wadsworth – Thomson Learning
Fungi and Plants
• Plant diseases– Lower fungi
• 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
© 2004 Wadsworth – Thomson Learning
Fungi and Humans
• Human disease– Mycoses
• 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
© 2004 Wadsworth – Thomson Learning
Algae
• Aquatic– freshwater– marine
• Terrestrial– moist soil– tree bark– surface of rocks
• Endophytic– live in other organisms
• Varied environments
• Commercial– Carageenan
• thickener
– Agar– Alginic acid
• thickener
– Food• protein supplement
• animal food
© 2004 Wadsworth – Thomson Learning
Algae
• Classification– Six groups
– form of thalli– wall structure– pigments
• Euglenoids• Dinoflagellates• Diatoms• Green algae• Brown algae• Red algae
Figure 12.12
© 2004 Wadsworth – Thomson Learning
Lichens
• Mutualistic association– fungus– phototroph
• algae• cyanobacteria
Figure 12.13
© 2004 Wadsworth – Thomson Learning
Protozoa
• Four groups– based on motility
– Flagellate • Mastigophora
– Amoeboid• Sarcodina• pseudopods
– Sporozoa• nonmotile
– Ciliate• cilia
Figure 12.14
© 2004 Wadsworth – Thomson Learning
Slime molds
• Not fungi
• Two groups– True slime molds
• Slimy, veined mass• Multinucleated cytoplasm
– Cellular slime molds• Cells resemble amoeboid protozoa• Dictyostelium discoideum
– Morphological changes in life cycle
© 2004 Wadsworth – Thomson Learning
Relatedness of Eukaryotes
Figure 12.19
© 2004 Wadsworth – Thomson Learning
Helminths
• Flatworms– tapeworms
• scolex– attachment– hooks/sucker
• germinal center– new segments
• proglottids– segments
– flukes
• Roundworms– nematodes
Figure 12.20
© 2004 Wadsworth – Thomson Learning
Life Cycle of Beef Tapeworm
Figure 12.21
© 2004 Wadsworth – Thomson Learning
Arthropod Vectors
• Reservoir of infection– mechanical vector
• external transmission• not essential link
– biological vector• part of life cycle• internal transmission
Figure 12.23