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

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

Mycology: The Study of Fungi Table 12.2

Fungi Table 12.1

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

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

Dimorphism Pathogenic dimorphic fungi are yeastlike at 37°C and moldlike at 25°C Figure 12.4

Fungal Life Cycle Figure 12.7

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 normally

Asexual spores Sporangiosphore Conidiospore Arthrospore Blastoconidium Chlamydospore Figure 12.1

Conidiospores Figure 12.5

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

Sexual spores Zygospore Fusion of haploid cells produces one zygospore Figure 12.6

Sexual spores Ascospore Formed in a sac (ascus) Figure 12.7

Sexual spores Basidiospore Formed externally on a pedestal (basidium) Figure 12.8

The Protozoa Table 12.1

Protozoa Eukaryotic Unicellular Chemoheterotrophs Vegetative form is a trophozoite Asexual reproduction by fission, budding, or schizogony Sexual reproduction by conjugation Some produce cysts Figure 12.16

Archaezoa No mitochondria Multiple flagella Giardia lamblia Trichomonas vaginalis (no cyst stage) Figure 12.17b-d

Rhizopoda (amoebas) Move by pseudopods Entamoeba No jpeg for Figure 21.21 Figure 12.18a

Apicomplexa Nonmotile Intracellular parasites Complex life cycles Such as Plasmodium

Plasmodium 1 2 9 3 Sexual reproduction Asexual reproduction 8 4 5 7 6 Infected mosquito bites human; sporozoites migrate through bloodstream to liver of human 2 Sporozoites undergo schizogony in liver cell; merozoites are produced Sporozoites in salivary gland 9 Resulting sporozoites migrate to salivary glands of mosquito 3 Merozoites released into bloodsteam from liver may infect new red blood cells Sexual reproduction Asexual reproduction 8 In mosquito’s digestive tract, gametocytes unite to form zygote Zygote Intermediate host Female gametocyte 4 Merozoite develops into ring stage in red blood cell Male gametocyte Ring stage 5 Ring stage grows and divides, producing merozoites Definitive host 7 Another mosquito bites infected humnan and ingests gametocytes 6 Merozoites are released when red blood cell ruptures; some merozoites infect new red blood cells, and some develop into male and female gametocytes Merozoites Figure 12.19

Ciliophora (ciliates) Moves by cilia Balantidium coli is the only human ciliates. Figure 12.20

Euglenozoa Move by flagella Trypanosoma Undulating membrane, transmitted by TseTse fly

Euglenozoa Leishmania Flagellated form in sand fly vector, ovoid form in vertebrate host

The Helminths Table 12.1

Helminths (parasitic worms) Eukaryotic Multicellular animals Chemoheterotrophic Kingdom: Animalia Phylum: Platyhelminthes (flatworms) Class: Trematodes (flukes) e .g Schistosoma Class: Cestodes (tapeworms) e .g tainia Phylum: Nematodes (roundworms) e. g Ascaris and pin worms

Schistosoma

Tainia Figure 12.27

Pin worms Figure 12.29

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 (vectors) Figure 12.31, 32

Arthropods as Vectors Figure 12.33