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ALGAE, FUNGI, and PROTOZOANS Chapter 12, pp 299-322


I. Algae = diverse group of eukaryotes - generally oxygenic photosynthesis, but lack complex tissue differentiation of higher plants; generally classified by photosynthetic pigments present Table 12-1, p302

A) additional characteristics: eukaryote; reproduce sexually and asexually

B) macroscopic and microscopic forms (see phytoplankton p 301)

C) toxins - see page 303 (red tides, paralytic shellfish poisoning, Pfisteria )


II. Fungi (mycology) (the good, the bad, and the fuzzy) Table 12-3, p308
Includes yeasts, molds, and fleshy fungi (mushrooms); all are chemoheterotrophs, many
are saprophytes, a few are pathogens;

A) characteristics
1)molds = multicellular, filamentous; vegetative filaments = hyphae Fig 12-15,p309
hyphae can intertwine forming a mass or mycelium (vegetative or aerial)
Aerial projects above surface, bears reproductive spores

2) yeasts = unicellular, spherical, reproduce by budding (Fig 12-14, p 309);
Capable of facultative anaerobic growth generating ethanol and carbon dioxide

3) dimorphic fungi = exist as yeast or mold, generally temp dependent
e.g. yeast at 37°C, mold at 25°C

B) reproductive structures = spores - used to identify fungi
1) asexual spores - formed from aerial mycelium of one organism
2) sexual spores - results from sexual reproduction

C) nutritional requirements of fungi see text p310

D) medically important fungi (Table 12-4, p 312)
- usually not very contagious, more difficult to treat than bacterial diseases
(we will cover some of these in more detail later)

Terminology:
systemic = deep within/throughout body
subcutaneous = beneath the skin
cutaneous = epidermis, hair, nails
superficial = hair shafts, surface of epidermal cells
mycoses = fungal infections

1) Histoplasmosis = systemic mycoses (Histoplasma capsulatum )
2) Coccidioidomycosis - also systemic (Coccidioides immitis )

3) Cutaneous mycoses
- most caused by Trichophyton rubrum causing tineas (ringworm)
- Tinea capitis = scalp
- Tinea corporis = body
- Tinea pedis = feet
- Tineas unguium = nails
- Tineas versicolor = Malassezia furfur = rash on body, very superficial

4) Opportunistic fungal infections
-Candidiasis = Candida albicans causes oral thrush, vaginitis

5) Rhizopus nigricans = common black bread mold

6) Fungal toxins - text p 311(ergot, aflatoxins)

III. Protozoans

A) protozoans = unicellular, kingdom Protista, classified based on motility, most are
aerobic chemoheterotrophs, some may form protective capsules = cysts
(see Table 12-2, p 305)

1) Sarcodina = move by pseudopodia

2) Mastigophora = possess flagella

3) Ciliata = cilia

4) Sporozoa = lack motility


B) Protozoan diseases
(some require arthropod vectors Table 12-5, p315)

1) Amoebiasis (amoebic dysentery Entamoeba histolytica )

2) Giardiasis (Giardia lamblia )

3) Trypanosomiasis (Trypanosoma brucei ) = sleeping sickness

4) Plasmodium = malaria
- 5 species of Plasmodium infect humans

5) Toxoplasmosis = (Toxoplasma gondii )

6) Trichomoniasis = (Trichomonas vaginalis )

7) Opportunisitic respiratory tract infection (common in AIDS) =
Pneumocystis carinii

IV. Helminths (table 12-6, p318)

1) Nematodes

2) tapeworms

3) flukes

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