MICRO-f11_Ch12sound

Chapter 12: 

Chapter 12 The Eukaryotes: Fungi, Algae, Protozoa, & Helminths

Ch. 12 Objectives:: 

Ch. 12 Objectives: Using specific examples, distinguish between the life cycles and reproductive structures of the 3 major fungal divisions : basidiomycetes, ascomycetes, and zygomycetes . … ….. Distinguish between structural, cellular, metabolic, and human interaction characteristics between fungi, algae, protozoans, & helminths .

12.1) The Fungi: 

12.1) The Fungi Eukaryotic Aerobic or facultatively anaerobic Chemoheterotrophic Most are decomposers Mycology is the study of fungi

Mycology: The Study of Fungi: 

Mycology: The Study of Fungi

Fungal Diseases (mycoses): 

Systemic mycoses = Deep within body Subcutaneous mycoses = Beneath the skin Cutaneous mycoses = Affect hair, skin, nails Superficial mycoses = Localized, e.g., hair shafts Opportunistic mycoses = Caused by normal microbiota or fungi that are usually harmless Fungal Diseases (mycoses)

A. Molds: 

The fungal body consists of hyphae ; a mass of hyphae is a mycelium . A. Molds Figure 12.2

B. Yeasts: 

Unicellular fungi Fission yeasts divide symmetrically Budding yeasts divide asymmetrically B. Yeasts Figure 12.3

Fungal Dimorphism (2 forms): 

Pathogenic dimorphic fungi are: Yeast-like at 37°C and mold-like at 25°C Fungal Dimorphism (2 forms) Figure 12.4

Fungal (Zygomycete) Life Cycle: 

Fungal (Zygomycete) Life Cycle Fig. 12.6 Sexual spores Asexual spores DIPLOID! (2n) HAPLOID (n) HAPLOID (n) **

1. Asexual spores: 

Sporangiospore – encased . Conidiospore – naked . Chlamydospore – thick walled hypha ; Candida 1. Asexual spores Figure 12.1

2. Sexual reproduction: 

Plasmogamy = Haploid donor cell nucleus (+) penetrates cytoplasm of recipient cell (–) Karyogamy = + and – nuclei fuse Meiosis = Diploid nucleus produces haploid nuclei (sexual spores) 2. Sexual reproduction

Sexual spores  name of phylum: 

Zygospore = Fusion of haploid cells produces one zygospore Ascospore = Formed in a sac (ascus) Basidiospore = Formed externally on a pedestal Eg: within mushroom cap Sexual spores  name of phylum Figures 12.6-8 (basidium)

3. Fungal Phyla: 

Zygomycota = Conjugation fungi; Coenocytic . Rhizopus, Mucor (Opportunistic, systemic mycoses) Ascomycota = Sac fungi. Septate hyphae. Aspergillus (opportunistic, systemic mycosis) Microsporum, Trichophyton (cutaneous mycoses) Basidiomycota = Club fungi. Septate . Cryptococcus neoformans (systematic mycosis) Anamorphs = no defined forms; rRNA in Asco, basidio [ Teleomorphic fungi: Produce sexual and asexual spores.] Anamorphic fungi: Produce asexual spores only. Penicillium ; Pneumocystis (systemic mycoses); Candida albicans (Cutaneous mycoses) 3. Fungal Phyla

4. Economic Effects of Fungi: 

4. Economic Effects of Fungi Fungi Positive Effects Negative Effects Saccharomyces Bread, wine, beer Food spoilage Trichoderma Cellulase used for juices and fabric Cryphonectria parasitica (chestnut blight) Taxomyces Taxol production Ceratocystis ulm (Dutch elm disease) Entomorphaga Gypsy moth control; saved trees in eastern U.S

C. Lichens: 

Mutualistic combination of an alga (or cyanobacterium) & fungus. (** “Pioneer species”) Alga produces and secretes carbohydrates, Fungus provides holdfast & protection. C. Lichens Figure 12.9

12.2) The Algae: 

12.2) The Algae Eukaryotic Unicellular, filamentous, or multicellular (thallic) Most are photoautotrophs Green Algae ( Chlorophyta ) Red Algae ( Rhodophyta ) Brown Algae ( Phaeophyta )

Slide 17: 

Figure 12.11a agar and carrageenan algin Cellulose walls Chlorophylls  green plants!

D. Bacillariophyta: 

Diatoms : Pectin and silica cell walls Unicellular; Store oil photosynthate (not sucrose, glucose, or starch) Fossilized diatoms formed oil; = phytoplankton . Produce domoic acid neurotoxin D. Bacillariophyta Figure 12.12

E. Dinoflagellata: 

Dinoflagellates: = phytoplankton . Cellulose in PM ; Unicellular; Chlorophylls; starch 30% of earth’s oxygen! (> rainforests) Neurotoxins E. Dinoflagellata F. Oomycota (fungus-like!) Water molds; Cellulose; Chemoheterotrophic Decomposers and plant parasites Phytophthora infestans responsible for Irish potato blight P. ramorum causes sudden oak death Figure 12.15 Figure 12.13

12.3) The Protozoa: 

12.3) The Protozoa Eukaryotic Unicellular Chemoheterotrophs Asexual reproduction by fission, budding, or schizogony . Sexual reproduction by conjugation Some produce cysts . Figure 12.15

A. Archaezoa: 

No mitochondria Multiple flagella Giardia lamblia No mitochondria!! Trichomonas vaginalis (no cyst stage) A. Archaezoa Figure 12.16

B. Rhizopoda (amoebas): 

Move by pseudopods Entamoeba Acanthamoeba B. Rhizopoda (amoebas) Figure 12.17

C. Apicomplexa: 

Nonmotile Intracellular parasites Complex life cycles Cryptosporidium Plasmodium - malaria C. Apicomplexa

Plasmodium: 

Plasmodium Figure 12.18 *** ***

D. Ciliophora (ciliates): 

Move by cilia: Paramecium, Tetrahymena, Vorticella Complex cells Balantidium coli is the only human parasite D. Ciliophora (ciliates) Figure 12.19

E. Euglenozoa: 

Move by flagella. Photoautotrophs : Euglenoids (“ algae ”) Chemoheterotrophs: Trypanosoma = sleeping sickness Undulating membrane, transmitted by vectors. E. Euglenozoa Figure 12.20

12.4) Slime Molds: 

12.4) Slime Molds Cellular slime molds Resemble amoebas, ingest bacteria by phagocytosis Cells aggregate into stalked fruiting body . Some cells become spores Plasmodial slime molds Multinucleated large cells Cytoplasm separates into stalked sporangia Nuclei undergo meiosis and form uninucleate haploid spores ** Fungus-like Protozoans; something like the Oomycota.

A. Cellular Slime Mold: 

A. Cellular Slime Mold Figure 12.21

B. Plasmodial Slime Mold: 

B. Plasmodial Slime Mold Figure 12.22 n 2n 2n 2n n n 2n

12.5) The Helminths: 

12.5) The Helminths Table 12.1

Helminths (parasitic worms): 

Helminths (parasitic worms) Eukaryotic Multicellular animals Chemoheterotrophic Kingdom: Animalia !!!! Phylum: Platyhelminthes (flatworms) Class: Trematodes (flukes) Class: Cestodes (tapeworms) Phylum: Nematodes (roundworms)

A. Cestodes – tapeworms: 

A. Cestodes – tapeworms Figure 12.26 Hermaphroditic Figure 12.27 Humans as Intermediate Host

B. Nematodes: Larvae Infective in Humans: 

B. Nematodes: Larvae Infective in Humans Figure 25.25

Arthropods as Vectors: 

Kingdom: Animalia Phylum: Arthropoda (exoskeleton, jointed legs) Class: Insecta (6 legs) Lice, fleas, mosquitoes Class: Arachnida (8 legs ) Mites and ticks May transmit diseases (disease vectors) Arthropods as Vectors Figure 12.30-32