Chapter 12: Fungi, Algae, Protozoa, and Parasites Fungi, Algae, Protozoa, and Parasites.

Chapter 12:Chapter 12:

Fungi, Algae, Protozoa, and Fungi, Algae, Protozoa, and

ParasitesParasites

I. I. FUNGI (Mycology)FUNGI (Mycology) Diverse group of heterotrophs.Diverse group of heterotrophs.

Many are ecologically important Many are ecologically important saprophytessaprophytes (consume dead and (consume dead and decaying matter)decaying matter)

Others are parasites. Others are parasites.

Most are multicellular, but yeasts are unicellular.Most are multicellular, but yeasts are unicellular. Most are aerobes or facultative anaerobes.Most are aerobes or facultative anaerobes. Cell walls are made up of Cell walls are made up of chitinchitin (polysaccharide). (polysaccharide). Over 100,000 fungal species identified. Only Over 100,000 fungal species identified. Only

about 200 are human or animal pathogens.about 200 are human or animal pathogens. Most human fungal infections are nosocomial and/or occur in Most human fungal infections are nosocomial and/or occur in

immunocompromised individuals (opportunistic infections).immunocompromised individuals (opportunistic infections).

Fungal diseases in plants cause over 1 billion Fungal diseases in plants cause over 1 billion dollars/year in losses.dollars/year in losses.

CHARACTERISTICSCHARACTERISTICS OFOF FUNGI FUNGI

1. Yeasts1. Yeasts

Unicellular fungi, nonfilamentous, typically oval or Unicellular fungi, nonfilamentous, typically oval or

spherical cells. Reproduce by mitosis:spherical cells. Reproduce by mitosis: Fission yeastsFission yeasts: Divide evenly to produce two new cells : Divide evenly to produce two new cells

((SchizosaccharomycesSchizosaccharomyces).).

Budding yeastsBudding yeasts: Divide unevenly by budding (: Divide unevenly by budding (Saccharomyces)Saccharomyces)..

Budding yeasts can form Budding yeasts can form pseudohyphapseudohypha, a short chain of , a short chain of

undetached cells.undetached cells.

Candida albicans Candida albicans invade tissues through pseudohyphae.invade tissues through pseudohyphae.

Yeasts are facultative anaerobes, which allows them to Yeasts are facultative anaerobes, which allows them to

grow in a variety of environments.grow in a variety of environments. When oxygen is available, they carry out aerobic respiration.When oxygen is available, they carry out aerobic respiration.

When oxygen is not available, they ferment carbohydrates to produce When oxygen is not available, they ferment carbohydrates to produce

ethanol and carbon dioxide.ethanol and carbon dioxide.

CHARACTERISTICSCHARACTERISTICS OFOF FUNGI (Continued)FUNGI (Continued)

2. Molds and Fleshy Fungi2. Molds and Fleshy Fungi Multicellular, filamentous fungi.Multicellular, filamentous fungi. Identified by physical appearance, colony characteristics, Identified by physical appearance, colony characteristics,

and reproductive spores.and reproductive spores. ThallusThallus: Body of a mold or fleshy fungus. Consists of many : Body of a mold or fleshy fungus. Consists of many

hyphae.hyphae. HyphaeHyphae (Sing: Hypha): Long filaments of cells joined together. (Sing: Hypha): Long filaments of cells joined together.

Septate hyphae:Septate hyphae: Cells are divided by cross-walls (septa). Cells are divided by cross-walls (septa). Coenocytic (Aseptate) hyphaeCoenocytic (Aseptate) hyphae: Long, continuous: Long, continuous cells that are cells that are

not divided by septa.not divided by septa.

Hyphae grow by elongating at the tips.Hyphae grow by elongating at the tips.

Each part of a hypha is capable of growth.Each part of a hypha is capable of growth. Vegetative HyphaVegetative Hypha: Portion that obtains nutrients.: Portion that obtains nutrients. Reproductive or Aerial HyphaReproductive or Aerial Hypha: Portion connected with : Portion connected with

reproduction.reproduction. MyceliumMycelium: Large, visible, filamentous mass made up of many : Large, visible, filamentous mass made up of many

hyphae.hyphae.

Characteristics of Fungal Hyphae:Septate versus Coenocytic

Mycelium: Large, Visible Mass of Hyphae

CHARACTERISTICSCHARACTERISTICS OFOF FUNGI (Continued)FUNGI (Continued)

Dimorphic FungiDimorphic Fungi

Can exist as both multicellular fungi (molds) and yeasts.Can exist as both multicellular fungi (molds) and yeasts.

Many pathogenic species.Many pathogenic species. Mold form produces aerial and vegetative hyphae.Mold form produces aerial and vegetative hyphae.

Yeast form reproduces by budding.Yeast form reproduces by budding.

Dimorphism in pathogenic fungi typically depends on Dimorphism in pathogenic fungi typically depends on

temperature:temperature: At 37At 37ooC: Yeast form.C: Yeast form.

At 25At 25ooC: Mold form.C: Mold form.

Dimorphism in nonpathogenic fungi may depend on other Dimorphism in nonpathogenic fungi may depend on other

factors: Carbon dioxide concentration.factors: Carbon dioxide concentration.

LIFELIFE CYCLECYCLE OFOF FUNGIFUNGI Filamentous fungi can reproduce asexually by Filamentous fungi can reproduce asexually by

fragmentation of their hyphae.fragmentation of their hyphae.

Fungal sporesFungal spores are formed from aerial hyphae and are are formed from aerial hyphae and are

used for both sexual and asexual reproduction.used for both sexual and asexual reproduction.

1. Asexual spores1. Asexual spores: Formed by the aerial hyphae of one organism. : Formed by the aerial hyphae of one organism.

New organisms are identical to parent.New organisms are identical to parent.

ConidiosporeConidiospore: Unicellular or multicellular spore that is not : Unicellular or multicellular spore that is not

enclosed in a sac.enclosed in a sac.

ChlamydosporeChlamydospore: Thick-walled spore formed within a hyphal : Thick-walled spore formed within a hyphal

segment.segment.

SporangiosporeSporangiospore: Asexual spore formed within a sac : Asexual spore formed within a sac

(sporangium).(sporangium).

2. Sexual spores2. Sexual spores: Formed by the fusion of nuclei from two opposite : Formed by the fusion of nuclei from two opposite

mating strains of the same species. New organisms are different mating strains of the same species. New organisms are different

from both parents.from both parents.

IMPORTANTIMPORTANT DIVISIONSDIVISIONS OFOF FUNGIFUNGI

1. Anamorphs1. Anamorphs Not known to produce sexual spores. Not known to produce sexual spores.

Reproduce asexually.Reproduce asexually.

Recently reclassified.Recently reclassified. Candida albicansCandida albicans: Causes yeast infections of vagina in : Causes yeast infections of vagina in

women. Opportunistic infections of mucous women. Opportunistic infections of mucous

membranes in AIDS patients.membranes in AIDS patients.

Pneumocystis cariniiPneumocystis carinii: Causes pneumonia in AIDS : Causes pneumonia in AIDS

patients. Leading cause of death in AIDS patients. patients. Leading cause of death in AIDS patients.

Originally classified as a protozoan.Originally classified as a protozoan.

Opportunistic Infection by Candida albicans in an AIDS Patient

Source: Atlas of Clinical Oral Pathology, 1999

2. Teleomorphs2. Teleomorphs

Produce both sexual and asexual spores.Produce both sexual and asexual spores.

A. Zygomycota (Conjugation Fungi)A. Zygomycota (Conjugation Fungi) Also known as bread molds. Also known as bread molds. Saprophytic molds with Saprophytic molds with coenocyticcoenocytic hyphae (lack septa). hyphae (lack septa).

Asexual ReproductionAsexual Reproduction: Used most of the time. : Used most of the time.

SporangiosporeSporangiospore: Asexual spore enclosed within a : Asexual spore enclosed within a sporangiumsporangium or balloon- or balloon-like sac at the end on an aerial hypha.like sac at the end on an aerial hypha.

Sexual ReproductionSexual Reproduction: Occurs through : Occurs through conjugationconjugation, the joining of hypha , the joining of hypha of two different strains (plus and minus).of two different strains (plus and minus).

Zygospores:Zygospores: Sexual spores are enclosed in a thick wall. Sexual spores are enclosed in a thick wall.

Generally not pathogens.Generally not pathogens. Rhizopus nigricansRhizopus nigricans: Common black bread mold. May cause : Common black bread mold. May cause

opportunistic infections in diabetes patientsopportunistic infections in diabetes patients

Life Cycle of a Zygomycete: Black Bread Mold (Rhizopus)Reproduces Asexually and Sexually

Reproductive Structures of Zygomycete (Rhizopus)Sporangia (asexual) and Zygospore (sexual)

IMPORTANTIMPORTANT DIVISIONSDIVISIONS OFOF FUNGIFUNGIB. Ascomycota (Sac Fungi)B. Ascomycota (Sac Fungi) Molds with septate hyphae and some yeasts.Molds with septate hyphae and some yeasts.

Asexual ReproductionAsexual Reproduction: : ConidiaConidia means dust. means dust.

ConidiosporesConidiospores notnot enclosed in a sac. Become airborne enclosed in a sac. Become airborne

easily. Form chains (broom-like structures).easily. Form chains (broom-like structures).

Sexual ReproductionSexual Reproduction: : AscosporesAscospores enclosed in a enclosed in a sac-likesac-like

structure (structure (ascusascus).). Include common antibiotic producing fungi and yeasts, Include common antibiotic producing fungi and yeasts,

and several human pathogens.and several human pathogens. Penicillium notatumPenicillium notatum (Produces penicillin)(Produces penicillin) SaccharomycesSaccharomyces (Brewer’s yeast)(Brewer’s yeast) TrychophytonTrychophyton (Athlete’s foot)(Athlete’s foot) AspergillusAspergillus (Carcinogenic aflatoxin in peanuts)(Carcinogenic aflatoxin in peanuts),, BlastomycesBlastomyces (Respiratory infections)(Respiratory infections) Histoplasma capsulatumHistoplasma capsulatum (Respiratory and systemic infections)(Respiratory and systemic infections)

Life Cycle of Eupenicillium (Ascomycete)Reproduces Asexually and Sexually

Athlete’s Foot (Tinea pedis)

Source: Doctorfungus Corporation, 2000

Severe nail infection with Trichophyton rubrum ina 37-year-old male AIDS patient.Source: Intern. J. Dermatol. 31(1992): 453.

Disseminated Histoplasma capsulatum, skin infection.Source: Microbiology Perspectives, 1999.

C. Basidiomycota (Club Fungi)C. Basidiomycota (Club Fungi) Have septate hyphae.Have septate hyphae.

Include mushrooms, toadstools, rusts, and smuts.Include mushrooms, toadstools, rusts, and smuts.

Sexual ReproductionSexual Reproduction: Produce : Produce basidiosporesbasidiospores: Spores : Spores

formed externally on a club shaped sexual structure or formed externally on a club shaped sexual structure or

base called base called basidiumbasidium. .

Asexual ReproductionAsexual Reproduction: Through hyphae.: Through hyphae.

Examples:Examples: Cryptococcus neoformans: Cryptococcus neoformans: Causes opportunistic respiratory and Causes opportunistic respiratory and

CNS infections in AIDS patients.CNS infections in AIDS patients.

Amanita: Amanita: Mushroom produces lethal toxins to humans.Mushroom produces lethal toxins to humans.

Claviceps purpurea:Claviceps purpurea: Produces ergot toxin in wheat and rye. Produces ergot toxin in wheat and rye.

Life Cycle of a BasidiomyceteMushrooms are Produced Sexually

NUTRITIONALNUTRITIONAL ADAPTATIONSADAPTATIONS OFOF FUNGIFUNGI

Fungi Fungi absorbabsorb their food, rather than ingesting it. their food, rather than ingesting it.

Fungi grow better at a pH of 5, which is too Fungi grow better at a pH of 5, which is too acidicacidic for for

most bacteria.most bacteria.

Almost all molds are Almost all molds are aerobicaerobic. Most yeasts are . Most yeasts are facultative facultative

anaerobes.anaerobes.

Fungi are more Fungi are more resistantresistant to to high osmotic pressurehigh osmotic pressure than than

bacteria.bacteria.

Fungi can grow on substances with very Fungi can grow on substances with very low moisturelow moisture..

Fungi require less nitrogen than bacteria to grow.Fungi require less nitrogen than bacteria to grow.

Fungi can break down complex carbohydrates (wood, Fungi can break down complex carbohydrates (wood,

paper), that most bacteria cannot.paper), that most bacteria cannot.

FUNGALFUNGAL DISEASESDISEASES

Mycosis:Mycosis: Any fungal disease. Tend to be chronic because Any fungal disease. Tend to be chronic because

fungi grow slowly. fungi grow slowly.

Mycoses are classified into the following categories:Mycoses are classified into the following categories:

I. SystemicI. Systemic mycosesmycoses: Fungal infections deep within the : Fungal infections deep within the

body. Can affect a number if tissues and organs.body. Can affect a number if tissues and organs.

Usually caused by fungi that live in the soil and are Usually caused by fungi that live in the soil and are

inhaled. Not contagious.inhaled. Not contagious.

Examples:Examples: HistoplasmosisHistoplasmosis ( (Histoplasma capsulatumHistoplasma capsulatum): Initial infection in ): Initial infection in

lungs. Later spreads through blood to most organs.lungs. Later spreads through blood to most organs.

CoccidiomycosisCoccidiomycosis ( (Coccidioides immitesCoccidioides immites): Resembles tuberculosis.): Resembles tuberculosis.

Systemic Mycosis: Histoplasmosis

Disseminated Histoplasma capsulatum, lung infection.Source: Microbiology Perspectives, 1999.

FUNGALFUNGAL DISEASES (Continued)DISEASES (Continued)

II. CutaneousII. Cutaneous mycosesmycoses: Fungal infections of the skin, hair, : Fungal infections of the skin, hair,

and nails. and nails.

Secrete keratinase, an enzyme that degrades keratin.Secrete keratinase, an enzyme that degrades keratin.

Infection is transmitted by direct contact or contact with Infection is transmitted by direct contact or contact with

infected hair (hair salon) or cells (nail files, shower infected hair (hair salon) or cells (nail files, shower

floors).floors).

Examples:Examples: RingwormRingworm ( (Tinea capitisTinea capitis and and T. corporisT. corporis))

Athlete’s footAthlete’s foot ( (Tinea pedisTinea pedis))

Jock itchJock itch ( (Tinea crurisTinea cruris))

Cutaneous Mycosis

Ringworm skin infection: Tinea corporisSource: Microbiology Perspectives, 1999

Cutaneous Mycosis: Jock Itch

Ringworm skin infection: Tinea crurisSource: DermNet.com

Cutaneous Mycosis

Candida albicans infection of the nails.Source: Microbiology Perspectives, 1999.


III. SubcutaneousIII. Subcutaneous mycosesmycoses: Fungal infections beneath the : Fungal infections beneath the

skin. skin.

Caused by saprophytic fungi that live in soil or on Caused by saprophytic fungi that live in soil or on

vegetation. vegetation.

Infection occurs by implantation of spores or mycelial Infection occurs by implantation of spores or mycelial

fragments into a skin wound. fragments into a skin wound.

Can spread to lymph vessels. Can spread to lymph vessels.

IV. Superficial mycosesIV. Superficial mycoses: Infections of hair shafts and : Infections of hair shafts and

superficial epidermal cells. Prevalent in tropical climates.superficial epidermal cells. Prevalent in tropical climates.


Opportunistic mycosesOpportunistic mycoses: Caused by organisms that are : Caused by organisms that are

generally harmless unless individual has weakened generally harmless unless individual has weakened

defenses:defenses: AIDS, cancer, transplant, and diabetic patientsAIDS, cancer, transplant, and diabetic patients

Individuals treated with broad spectrum antibioticsIndividuals treated with broad spectrum antibiotics

Very old or very young individuals (newborns).Very old or very young individuals (newborns).

Examples:Examples: AspergillosisAspergillosis: Inhalation of : Inhalation of AspergillusAspergillus spores. spores.

Yeast Infections or Candidiasis:Yeast Infections or Candidiasis: Caused mainly by Caused mainly by Candida Candida

albicansalbicans. Part of normal mouth, esophagus, and vaginal flora.. Part of normal mouth, esophagus, and vaginal flora.

ECONOMIC IMPORTANCE OF FUNGIECONOMIC IMPORTANCE OF FUNGI 25-50% of harvested25-50% of harvested fruits and vegetables are damaged fruits and vegetables are damaged

by fungi.by fungi.

Fungal infections of plants are commonly called rots, Fungal infections of plants are commonly called rots,

rusts, blights, wilts, and smuts.rusts, blights, wilts, and smuts.

Beneficial fungi:Beneficial fungi: Candida oleophilaCandida oleophila: Prevents fungal growth on harvested fruits.: Prevents fungal growth on harvested fruits.

Saccharomyces cerevisiaeSaccharomyces cerevisiae: Used to make bread and wine. : Used to make bread and wine.

Genetically engineered yeast strainsGenetically engineered yeast strains are used to make proteins are used to make proteins

(Hepatitis B vaccine).(Hepatitis B vaccine).

TaxomycesTaxomyces: Produces anticancer drug taxol.: Produces anticancer drug taxol.

TrichodermaTrichoderma: Produces cellulase. Used to make fruit juice.: Produces cellulase. Used to make fruit juice.

Saccharomyces boulardiSaccharomyces boulardi: Used as probiotic because it kills other : Used as probiotic because it kills other

yeast.yeast.

II. II. ALGAE ALGAE Most are simple eucaryotic photosynthetic autotrophs.Most are simple eucaryotic photosynthetic autotrophs.

Unicellular or multicellular. Kingdom Protista.Unicellular or multicellular. Kingdom Protista.

Most are found in the ocean or other bodies of water. Most are found in the ocean or other bodies of water.

Need water for support, reproduction, and nutrition.Need water for support, reproduction, and nutrition.

Absorb nutrients from the water over entire surface.Absorb nutrients from the water over entire surface.

Reproduction: All reproduce asexually. Some can also Reproduction: All reproduce asexually. Some can also

reproduce sexually.reproduce sexually.

Most are not pathogens. A few produce toxins that are Most are not pathogens. A few produce toxins that are

harmful to humans.harmful to humans.

II. II. ALGAE ALGAE Vegetative Structures of multicellular algae:Vegetative Structures of multicellular algae:

Thallus: Body. Lacks conductive tissue.Thallus: Body. Lacks conductive tissue.

Holdfasts: Anchor alga to rock.Holdfasts: Anchor alga to rock.

Stipes: Hollow, stem-like structures. Does not Stipes: Hollow, stem-like structures. Does not

support weight.support weight.

Blades: Leaf-like structures.Blades: Leaf-like structures.

Pneumatocyst: Floating, gas-filled bladder.Pneumatocyst: Floating, gas-filled bladder.

Comparison of Algae and Plant Structure

DIVISIONS OF ALGAEDIVISIONS OF ALGAE Green algaeGreen algae: May be unicellular or multicellular. : May be unicellular or multicellular.

Have cellulose cell walls, contain chlorophyll a and b, and Have cellulose cell walls, contain chlorophyll a and b, and

store starch like plants. Most are microscopic. Live close store starch like plants. Most are microscopic. Live close

to water surface. Believed to be the ancestors of to water surface. Believed to be the ancestors of

terrestrial plants.terrestrial plants.

Brown Algae or KelpBrown Algae or Kelp: Macroscopic (up to 50 m long). : Macroscopic (up to 50 m long).

Most are found in coastal waters, at intermediate depths. Most are found in coastal waters, at intermediate depths.

Rapid growth. Can be harvested regularly.Rapid growth. Can be harvested regularly.

Red AlgaeRed Algae: Live at greater ocean depths than other : Live at greater ocean depths than other

algae. Red pigments allow them to absorb blue light that algae. Red pigments allow them to absorb blue light that

penetrates deepest into ocean. Agar is extracted from penetrates deepest into ocean. Agar is extracted from

many red algae. Some produce lethal toxins.many red algae. Some produce lethal toxins.

Seaweed is a Multicellular Brown Alga (Laminaria)

DIVISIONS OF ALGAE (Continued)DIVISIONS OF ALGAE (Continued)

DiatomsDiatoms: Unicellular or filamentous algae with complex : Unicellular or filamentous algae with complex

cell walls with silica or calcium. cell walls with silica or calcium.

TwoTwo parts of cell wall fit together like Petri dish. parts of cell wall fit together like Petri dish.

Distinctive patterns are used for identification. Store Distinctive patterns are used for identification. Store

energy in form of oil.energy in form of oil.

Some diatoms can cause neurological disease (memory Some diatoms can cause neurological disease (memory

loss and diarrhea) in people who eat mussels, due to loss and diarrhea) in people who eat mussels, due to

domoic acid intoxicationdomoic acid intoxication..

Fossil deposits of diatoms (diatomaceous earth) are Fossil deposits of diatoms (diatomaceous earth) are

used as filtering agents and abrasives in several used as filtering agents and abrasives in several

industriesindustries..

Dinoflagellates (Plankton)Dinoflagellates (Plankton): Unicellular free-floating : Unicellular free-floating algae. Rigid structure due to cellulose in plasma algae. Rigid structure due to cellulose in plasma membrane. membrane.

Some dinoflagellates produce neurotoxins, which kill fish, Some dinoflagellates produce neurotoxins, which kill fish, marine mammals, and humans. marine mammals, and humans. Paralytic shellfish poisoningParalytic shellfish poisoning: Consumption of clams and mussels : Consumption of clams and mussels

that have eaten dinoflagellates (that have eaten dinoflagellates (Alexandrium sppAlexandrium spp..)) that produce that produce

neurotoxin.neurotoxin.

Red TideRed Tide: Caused by large concentrations of : Caused by large concentrations of AlexandriumAlexandrium. Avoid . Avoid

harvesting mollusks and fish during red tide.harvesting mollusks and fish during red tide.

EuglenoidsEuglenoids: Unicellular, flagellated algae. Semi-rigid : Unicellular, flagellated algae. Semi-rigid

plasma membrane (pellicle). Most have anterior red eye plasma membrane (pellicle). Most have anterior red eye

spot. Frequently studied with protozoa, because lack a spot. Frequently studied with protozoa, because lack a

cell wall.cell wall.

Euglenoids are Flagellated, Unicellular Algae

Pathogenic AlgaePathogenic Algae Oomycota (Water Molds):Oomycota (Water Molds): Most are decomposers. Most are decomposers.

Form cottony masses on dead animals in water. Form cottony masses on dead animals in water.

Previously classified as fungi (zygomycetes).Previously classified as fungi (zygomycetes). Phytophthora infestansPhytophthora infestans: Caused great potato famine in : Caused great potato famine in

mid-1800s. Over 1 million people died from starvation mid-1800s. Over 1 million people died from starvation

in Ireland; many immigrated to the U.S. in Ireland; many immigrated to the U.S.

Also infects soybean, potatoes, and cocoa.Also infects soybean, potatoes, and cocoa.

http://de.wikipedia.org/wiki/Phytophthora_infestans

Ecological Importance of AlgaeEcological Importance of Algae Important part of the food chain in aquatic ecosystems Important part of the food chain in aquatic ecosystems

because they fix carbon dioxide into organic molecules because they fix carbon dioxide into organic molecules

that can be used by heterotrophs. that can be used by heterotrophs.

80% of the earth’s oxygen is believed to be produced by 80% of the earth’s oxygen is believed to be produced by

planktonic algae.planktonic algae.

Algal blooms are indicators of water pollution.Algal blooms are indicators of water pollution. Grow rapidly in water with high concentrations of organic Grow rapidly in water with high concentrations of organic

material (sewage or industrial waste).material (sewage or industrial waste).

Petroleum and natural gas reserves were formed Petroleum and natural gas reserves were formed

primarily from diatoms and plankton.primarily from diatoms and plankton.

Many unicellular algae are symbionts in animals.Many unicellular algae are symbionts in animals.

III. III. LICHENS LICHENS Combination of a green alga (or cyanobacterium) and a Combination of a green alga (or cyanobacterium) and a

fungus.fungus. Mutualistic relationship in which each partner benefits.Mutualistic relationship in which each partner benefits.

AlgaAlga: Provides nutrients by photosynthesis to fungus.: Provides nutrients by photosynthesis to fungus. FungusFungus: Provides attachment and protection from desiccation.: Provides attachment and protection from desiccation.

20,000 species of lichens occupy unique habitats, in which 20,000 species of lichens occupy unique habitats, in which either fungi or algae could not survive alone: rocks, either fungi or algae could not survive alone: rocks, cement, rooftops, trees, and newly exposed soil.cement, rooftops, trees, and newly exposed soil.

Grow very slowly, secreting acids that break down rocks.Grow very slowly, secreting acids that break down rocks. Accumulate nutrients needed for plant growth.Accumulate nutrients needed for plant growth. Sensitive to air pollution.Sensitive to air pollution. Major food source for tundra herbivores (caribou and Major food source for tundra herbivores (caribou and

reindeer).reindeer).

Lichens: Combinations of Fungi and Green Algae (or Cyanobacterium)

IV. IV. SLIME MOLDS SLIME MOLDS Have both fungal and animal characteristics.Have both fungal and animal characteristics.

Amoeboid stageAmoeboid stage Produce spores like fungiProduce spores like fungi

Eucaryotes, classified as protists.Eucaryotes, classified as protists. Cellular and plasmodial (acellular) slime molds.Cellular and plasmodial (acellular) slime molds.

Life Cycle of Cellular Slime Molds:Life Cycle of Cellular Slime Molds: Amoeba stage: Germinate from a spore.Amoeba stage: Germinate from a spore. Slug stage: Many amoebas aggregate and sheath forms. Slug stage: Many amoebas aggregate and sheath forms.

Migration.Migration. Fruiting body: Releases spores which germinate into amoebas.Fruiting body: Releases spores which germinate into amoebas.

Plasmodial (Acellular) Slime MoldsPlasmodial (Acellular) Slime Molds Mass of protoplasm with many nuclei (Mass of protoplasm with many nuclei (plasmodiumplasmodium).). Capable of sexual reproduction.Capable of sexual reproduction.

Life Cycle of a Cellular Slime Mold

V. V. PROTOZOA PROTOZOA Unicellular, chemoheterotrophic, eucaryotic organisms of Unicellular, chemoheterotrophic, eucaryotic organisms of

kingdom Protista (3-2000 kingdom Protista (3-2000 m).m). ProtozoanProtozoan means “first animal”. means “first animal”. 20,000 species, only a few are pathogens.20,000 species, only a few are pathogens. Most are free-living organisms that inhabit water and Most are free-living organisms that inhabit water and

soil. Some live in association with other organisms as soil. Some live in association with other organisms as parasites or symbionts.parasites or symbionts.

Reproduce asexually by fission, budding, or schizogony.Reproduce asexually by fission, budding, or schizogony. Some exhibit sexual reproduction Some exhibit sexual reproduction ((e.g.: e.g.: ParameciumParamecium)).. TrophozoiteTrophozoite: Vegetative stage which feeds upon bacteria : Vegetative stage which feeds upon bacteria

and particulate nutrients.and particulate nutrients. CystCyst: Some protozoa produce a protective capsule under : Some protozoa produce a protective capsule under

adverse conditions (toxins, scarce water, food, or oxygen).adverse conditions (toxins, scarce water, food, or oxygen).

V. V. PROTOZOA (Continued) PROTOZOA (Continued)

NutritionNutrition Most are heterotrophic aerobes. Intestinal protozoa can Most are heterotrophic aerobes. Intestinal protozoa can

grow anaerobically.grow anaerobically. Some ingest whole algae, yeast, bacteria, or smaller Some ingest whole algae, yeast, bacteria, or smaller

protozoans. Others live on dead and decaying matter. protozoans. Others live on dead and decaying matter. Parasitic protozoa break down and absorb nutrients from Parasitic protozoa break down and absorb nutrients from their hosts.their hosts.

Some transport food across the membrane. Some transport food across the membrane. Others have a protective covering (Others have a protective covering (pelliclepellicle) and required ) and required

specialized structures to take in food.specialized structures to take in food. Ciliates take in food through a cytostome.Ciliates take in food through a cytostome.

Digestion takes place in vacuoles.Digestion takes place in vacuoles. Waste may be eliminated through plasma membrane or Waste may be eliminated through plasma membrane or

an anal pore.an anal pore.

Medically Important Protozoa Medically Important Protozoa 1. Amoeboflagellates 1. Amoeboflagellates (Phylum Sarcomastigophora)(Phylum Sarcomastigophora)Move using pseudopods (false feet) or flagella.Move using pseudopods (false feet) or flagella.A. A. AmoebasAmoebas (Subphylum Sarcodina) (Subphylum Sarcodina) Move by extending blunt, lobelike projections Move by extending blunt, lobelike projections

(pseudopods).(pseudopods). Amoebas engulf food with pseudopods and phagocytize it.Amoebas engulf food with pseudopods and phagocytize it. Several species cause amoebic dysenteries of varying Several species cause amoebic dysenteries of varying

degrees of severity.degrees of severity. Entamoeba hystolyticaEntamoeba hystolytica:: Feeds on red blood cells. Produces Feeds on red blood cells. Produces

dysentery and extraintestinal cysts.dysentery and extraintestinal cysts. Dientamoeba fragilisDientamoeba fragilis:: Found in 4% of humans. Usually Found in 4% of humans. Usually

commensal. Can cause chronic, mild diarrhea.commensal. Can cause chronic, mild diarrhea. Other diseases include:Other diseases include:

Meningoencephalitis:Meningoencephalitis: Caused by Caused by Naegleria fowleriNaegleria fowleri.. Penetrate Penetrate nasal mucosa of swimmers in warm waters. Mortality rate nasal mucosa of swimmers in warm waters. Mortality rate almost 100%.almost 100%.

Keratitis:Keratitis: Caused by Caused by AcanthamoebaAcanthamoeba. Can cause blindness. . Can cause blindness. Associated with use of contact lenses.Associated with use of contact lenses.

B. B. FlagellatesFlagellates (Subphylum Mastigophora) (Subphylum Mastigophora) Move by one or more whiplike flagella. Some parasitic Move by one or more whiplike flagella. Some parasitic

flagellates have up to eight flagella.flagellates have up to eight flagella. Most are spindle shaped with flagella projecting from Most are spindle shaped with flagella projecting from

anterior end.anterior end. Outer membrane is a tough pellicle. Food is ingested Outer membrane is a tough pellicle. Food is ingested

through an oral groove or cytosotome.through an oral groove or cytosotome. Important pathogens:Important pathogens:

Trichomonas vaginalisTrichomonas vaginalis: Causes genital and urinary infections. Has : Causes genital and urinary infections. Has undulating membrane. Lacks a cyst stage. Transmitted sexually undulating membrane. Lacks a cyst stage. Transmitted sexually or by fomites.or by fomites.

Giardia lambliaGiardia lamblia: Causes a persistent intestinal infection (giardiasis) : Causes a persistent intestinal infection (giardiasis) with diarrhea, nausea, flatulence, and cramps. In U.S. most with diarrhea, nausea, flatulence, and cramps. In U.S. most common cause of waterborne diarrhea. About 7% of U.S. common cause of waterborne diarrhea. About 7% of U.S. population are healthy carriers.population are healthy carriers.

Trypanosoma brucei gambienseTrypanosoma brucei gambiense: Hemoflagellate (blood parasite). : Hemoflagellate (blood parasite). Causes African sleeping sickness. Transmitted by Tse-Tse fly.Causes African sleeping sickness. Transmitted by Tse-Tse fly.

Trypanosoma cruziTrypanosoma cruzi: Hemoflagellate that causes Chaga’s disease, a : Hemoflagellate that causes Chaga’s disease, a cardiovascular disease common in Texas and Latin America.cardiovascular disease common in Texas and Latin America. Transmitted by kissing bug living in mud houses or blood transfusions. Transmitted by kissing bug living in mud houses or blood transfusions. Can cause heart damage (heart failure, arrythmia over several years).Can cause heart damage (heart failure, arrythmia over several years).

Medically Important Protozoa (Continued) Medically Important Protozoa (Continued)

2. Apicomplexans2. Apicomplexans (Phylum Apicomplexa) (Phylum Apicomplexa)

Not motile in their mature form.Not motile in their mature form.

Obligate intracellular parasites.Obligate intracellular parasites.

Have specialized organelles at tip (Have specialized organelles at tip (apexapex) of cells that ) of cells that

penetrate host tissues.penetrate host tissues.

Complex life cycles. May have more than one host. Complex life cycles. May have more than one host.

Definitive hostDefinitive host: Harbors sexually reproducing form. : Harbors sexually reproducing form.

Intermediate hostIntermediate host: In which asexual reproduction : In which asexual reproduction

occurs.occurs.


2. Apicomplexans2. Apicomplexans (Phylum Apicomplexa) (Phylum Apicomplexa) Important pathogens:Important pathogens:

Plasmodium vivax Plasmodium vivax and and falciparumfalciparum:: Cause malaria in humans Cause malaria in humans

(intermediate host). (intermediate host).

Initially treated with quinine, drug resistance is a major problem Initially treated with quinine, drug resistance is a major problem

today. today.

Major cause of worldwide mortality: Kill 3 million people/year Major cause of worldwide mortality: Kill 3 million people/year

and infect 500 million.and infect 500 million.

Transmitted by Transmitted by AnophelesAnopheles mosquito (definitive host).mosquito (definitive host).

DDT was used extensively in 1960s in an attempt to eradicate the DDT was used extensively in 1960s in an attempt to eradicate the

mosquito vector.mosquito vector.

Successful vaccine not available yet.Successful vaccine not available yet.

Life Cycle of Plasmodium spp. the Infectious Agent of Malaria


2. Apicomplexans2. Apicomplexans (Phylum Apicomplexa) (Phylum Apicomplexa) Important pathogens:Important pathogens:

Toxoplasma gondiiToxoplasma gondii:: Causes toxoplasmosis in humans. Causes Causes toxoplasmosis in humans. Causes

blindness and lymphatic infections in adults. Dangerous to blindness and lymphatic infections in adults. Dangerous to

pregnant women, causes severe neurological defects in unborn pregnant women, causes severe neurological defects in unborn

children. Cats are part of life cycle, oocysts excreted in feces. children. Cats are part of life cycle, oocysts excreted in feces.

Contact with infected feces or meat are means of transmission.Contact with infected feces or meat are means of transmission.

CryptosporidiumCryptosporidium: Causes respiratory and gallbladder infections : Causes respiratory and gallbladder infections

in immunosuppressed individuals. Found in intestines of in immunosuppressed individuals. Found in intestines of

mammals and water. Major cause of death in AIDS patients.mammals and water. Major cause of death in AIDS patients.

Cyclospora cayetensisCyclospora cayetensis:: New parasite (1996) caused diarrhea New parasite (1996) caused diarrhea

associated with raspberries.associated with raspberries.


3. Ciliates3. Ciliates (Phylum Ciliophora) (Phylum Ciliophora)

Move and obtain food using cilia.Move and obtain food using cilia.

Only known human pathogen is Only known human pathogen is Balantidium coli, Balantidium coli, which which

causes a severe intestinal infection in pigs and humans. causes a severe intestinal infection in pigs and humans.

4. Microsporans4. Microsporans (Phylum Mycrospora) (Phylum Mycrospora)

Obligate intracellular parasites, lack mitochondria and Obligate intracellular parasites, lack mitochondria and

microtubules.microtubules.

Discovered in 1984 to cause chronic diarrhea and Discovered in 1984 to cause chronic diarrhea and

conjunctivitis, mainly in AIDS patients.conjunctivitis, mainly in AIDS patients.

Paramecium caudatum is a Ciliated ProtozoanConjugation Between Opposite Mating Strains

VI. VI. HELMINTHS (WORMS) HELMINTHS (WORMS)

CharacteristicsCharacteristics Eucaryotic, multicellular animals that Eucaryotic, multicellular animals that usuallyusually have have

digestive, circulatory, nervous, excretory, and digestive, circulatory, nervous, excretory, and reproductive systems.reproductive systems.

Worms with bilateral symmetry, head and tail, and tissue Worms with bilateral symmetry, head and tail, and tissue differentiation (endoderm, mesoderm, and ectoderm).differentiation (endoderm, mesoderm, and ectoderm).

Parasitic helminthsParasitic helminths spend most or all of their lives in host spend most or all of their lives in host and usually have the following specializations:and usually have the following specializations: May lack a digestive systemMay lack a digestive system. Absorb nutrients from host’s food, . Absorb nutrients from host’s food,

body fluids, or tissues. body fluids, or tissues. Have a Have a reduced nervous systemreduced nervous system.. Means of locomotion is reduced or absent.Means of locomotion is reduced or absent. Complex reproductive system. Individuals produce many eggs Complex reproductive system. Individuals produce many eggs

that can infect another host. that can infect another host.

VI. VI. HELMINTHS (Continued) HELMINTHS (Continued)

Two main groups (phyla)Two main groups (phyla) Platyhelminths (Flatworms)Platyhelminths (Flatworms) Nematoda (Roundworms)Nematoda (Roundworms)

Life CycleLife Cycle Extremely complexExtremely complex Intermediate hosts harbor larval (developmental) stage.Intermediate hosts harbor larval (developmental) stage. Definitive host harbors adult stage.Definitive host harbors adult stage. Sexual reproduction strategies:Sexual reproduction strategies:

DioeciousDioecious: Male and female reproductive organs are found in : Male and female reproductive organs are found in

separate individuals.separate individuals.

Monoecious (Hermaphroditic):Monoecious (Hermaphroditic): One animal has both male and One animal has both male and

female sex organs. Most hermaphrodites copulate with other female sex organs. Most hermaphrodites copulate with other

animals, a few copulate with themselves.animals, a few copulate with themselves.


I. Platyhelminths (Flatworms)I. Platyhelminths (Flatworms)

Flattened from front to back.Flattened from front to back.

Include:Include:

1. Trematodes or Flukes1. Trematodes or Flukes Leaf shaped bodiesLeaf shaped bodies Ventral and oral suckers for attachment and sucking fluids Ventral and oral suckers for attachment and sucking fluids

from host.from host. Some can absorb nutrients through their Some can absorb nutrients through their cuticlecuticle.. Named for host tissues in which adult lives.Named for host tissues in which adult lives.

Blood Fluke Blood Fluke (Schistosoma spp.(Schistosoma spp.)):: Cause schistosomiasis which Cause schistosomiasis which affects over 400,000 immigrants in U.S. and 200 million people affects over 400,000 immigrants in U.S. and 200 million people worldwide.worldwide.

Cause damage to blood vessels, liver, and many other organs.Cause damage to blood vessels, liver, and many other organs.

Live in waters contaminated with feces, burrow through skin of Live in waters contaminated with feces, burrow through skin of human and enter the circulatory system, particularly abdominal human and enter the circulatory system, particularly abdominal and pelvic veins.and pelvic veins.

Free-Living Flatworm Life Cycle of Blood FlukePlanaria (Schistosoma)



1. Trematodes or Flukes1. Trematodes or Flukes Asian Liver Fluke Asian Liver Fluke (Clonorchis sinensis(Clonorchis sinensis)):: Infests gallbladder, Infests gallbladder,

bile ducts, pancreatic ducts, causes biliary cirrhosis and jaundice. bile ducts, pancreatic ducts, causes biliary cirrhosis and jaundice.

Cannot be transmitted in U.S. because intermediate hosts are not Cannot be transmitted in U.S. because intermediate hosts are not

available.available.

Lung Fluke (Lung Fluke (Paragonius westermaniParagonius westermani):): Lives in bronchioles of Lives in bronchioles of

humans and other animals. 12 mm long. Infection from eating humans and other animals. 12 mm long. Infection from eating

undercooked crayfish.undercooked crayfish.

Asian Liver Fluke (Clonorchis sinensis)

Source: http://www.biosci.ohio-state.edu/~parasite/a-h.html



2. Cestodes or Tapeworms2. Cestodes or Tapeworms Long flat bodiesLong flat bodies Intestinal parasitesIntestinal parasites Lack a digestive system, absorb food through cuticle.Lack a digestive system, absorb food through cuticle.

Body Organization:Body Organization: Head or Head or scolexscolex has suckers for attachment. has suckers for attachment. Body is made up of segments called Body is made up of segments called proglottidsproglottids. .

Each proglottid has both male and female reproductive organs.Each proglottid has both male and female reproductive organs.

Proglottids farthest from head are mature and contain many Proglottids farthest from head are mature and contain many

fertilized eggs.fertilized eggs.

Cestode (Tapeworm) Body Structure:Scolex and Proglottids



Cestodes or Tapeworms (Continued)Cestodes or Tapeworms (Continued) Parasitic human tapeworms:Parasitic human tapeworms:

Beef Tapeworm Beef Tapeworm (Taenia saginata)(Taenia saginata):: Human is definitive host. Human is definitive host.

Can reach up to 6 meters in length, scolex is 2 mm long with Can reach up to 6 meters in length, scolex is 2 mm long with

hundreds of proglottids. Infection occurs by ingestion of hundreds of proglottids. Infection occurs by ingestion of

contaminated, undercooked beef (“measly beef”).contaminated, undercooked beef (“measly beef”).

Pork Tapeworm Pork Tapeworm (Taenia solium)(Taenia solium):: Human is definitive host. Human is definitive host.

Infection can occur from eating infected undercooked pork Infection can occur from eating infected undercooked pork

(rare in the U.S.) or from human to human contact. May cause (rare in the U.S.) or from human to human contact. May cause

cysticercosis.cysticercosis.

Echinococcus granulosus:Echinococcus granulosus: Dogs and coyotes are definitive Dogs and coyotes are definitive

hosts. Humans may become infected by contact with dog feces hosts. Humans may become infected by contact with dog feces

or saliva.or saliva.

Cysticercosis: Pork Tapeworm

http://www.biosci.ohio-state.edu/~parasite/cysticercosis.htmlhttp://www.thamburaj.com/cysticercosis.htm


II. Nematodes (Roundworms)II. Nematodes (Roundworms) Cylindrical body tapered at each end.Cylindrical body tapered at each end. Have a Have a complete digestive systemcomplete digestive system: mouth, intestine, and : mouth, intestine, and

anus. anus. Body is covered by tough cuticle that resists drying and Body is covered by tough cuticle that resists drying and

crushing.crushing. Most species are Most species are dioeciousdioecious: separate males and females.: separate males and females.

Males are smaller than females and have one or two spicules on Males are smaller than females and have one or two spicules on posterior end.posterior end.

Over 90,000 known species. Most are free-living. Only Over 90,000 known species. Most are free-living. Only about 50 are human parasites.about 50 are human parasites.

Life cycle of parasitic nematodes is simpler than that of Life cycle of parasitic nematodes is simpler than that of flatworms.flatworms.

Infections can be caused by eggs or larvae.Infections can be caused by eggs or larvae.

Comparison of Body Organization of Flatworms, Roundworms, and Earthworms

Flatworm

Earthworm

Roundworm

II. Nematodes (Roundworms) ContinuedII. Nematodes (Roundworms) Continued

Infectious eggsInfectious eggs Pinworm (Pinworm (Enterobius vermicularis)Enterobius vermicularis):: Spends entire life in human Spends entire life in human

host. Adults live in large intestine. Female lays eggs in perianal host. Adults live in large intestine. Female lays eggs in perianal region which causes itching. Up to 90% of children are infected region which causes itching. Up to 90% of children are infected through contaminated clothes or bedding. Infection usually through contaminated clothes or bedding. Infection usually disappears after a few years.disappears after a few years.

Ascaris (Ascaris (Ascaris lumbricoides)Ascaris lumbricoides):: Large nematode, up to 30 cm. Large nematode, up to 30 cm. Dioecious with sexual dimorphism. Live in small intestines of Dioecious with sexual dimorphism. Live in small intestines of humans, horses, and pigs. Eggs can survive in soil for long time.humans, horses, and pigs. Eggs can survive in soil for long time.

Infectious larvaeInfectious larvae Adult Hookworm (Adult Hookworm (Necator americanus):Necator americanus): Live in small intestine of Live in small intestine of

humans, eggs are excreted in feces. Enter host by penetrating skin. humans, eggs are excreted in feces. Enter host by penetrating skin. Enters bloodstream, travels to lungs, swallowed in sputum. Enters bloodstream, travels to lungs, swallowed in sputum. Avoided by wearing shoes.Avoided by wearing shoes.

Trichinosis (Trichinosis (Trichinella spiralis):Trichinella spiralis): Reproduce sexually in small Reproduce sexually in small intestine of humans. Obtained from eating undercooked pork. intestine of humans. Obtained from eating undercooked pork. Larvae enter blood vessels and form cysts throughout body.Larvae enter blood vessels and form cysts throughout body.

Anisakines (Wriggly worms):Anisakines (Wriggly worms): Infected fish and squid. Killed by Infected fish and squid. Killed by freezing and cooking.freezing and cooking.

Pinworm (Enterobius vermicularis)


Pinworm Eggs (Enterobius vermicularis)


Ascaris (Ascaris lumbricoides)


Head of Ascaris (Ascaris lumbricoides)

Notice three lips characteristic of AscarisSource: www. soton.ac.uk/~djab/ascaris.html

VII. Arthropods as Vectors VII. Arthropods as Vectors Segmented bodies, hard exoskeleton (chitin), and jointed Segmented bodies, hard exoskeleton (chitin), and jointed

legs.legs. Largest phylum in animal kingdom, over 1 million Largest phylum in animal kingdom, over 1 million

species.species. Several classes of arthropods:Several classes of arthropods:

Arachnida (8 legs):Arachnida (8 legs): Spiders, mites, and ticks. Spiders, mites, and ticks.

Crustacea (4 antennae):Crustacea (4 antennae): Crabs, crayfish. Most are aquatic. Crabs, crayfish. Most are aquatic.

Insecta (6 legs):Insecta (6 legs): Largest group of living organisms on earth. Largest group of living organisms on earth.

Include bees, flies, lice, cockroaches, mosquitoes, and fleas. Include bees, flies, lice, cockroaches, mosquitoes, and fleas.

Arthropods that transmit microbial diseases are called Arthropods that transmit microbial diseases are called vectorsvectors..

How do arthropod vectors transport microbes? How do arthropod vectors transport microbes? MechanicallyMechanically: Houseflies and cockroaches.: Houseflies and cockroaches. HostsHosts: Tick vectors of Lyme disease.: Tick vectors of Lyme disease.

Mosquito vectors of malaria and encephalitis.Mosquito vectors of malaria and encephalitis.

Arachnids are Arthropods with Eight Legs

Lyme Disease Vector Spotted Mountain Fever and Tularemia Vector

Source: www. soton.ac.uk/~djab/ascaris.html

Scabies (Sarcoptes scabei)Infestation of the skin by microscopic mite (arachnid).Transmission: Prolonged skin to skin contact and fomites(e.g.: clothing and bedding). Common during water shortages.

Symptoms: Appear between 1 day to 6 weeks after exposure.• Vesicular or pimple like lesions and rashes of the skin• Intense itching worse at night• Allergic reaction to mites• Bleeding and scabbing from scratching• Sores on body caused by scratching may become infected• Norwegian scabies may occur in immunocompromised individuals with extensive scaling and crusting

Treatment: Several creams and lotions have been approved by FDA to treat mite infestations. Risky for pregnant women.

SCABIES (Sarcoptes scabiei)

Scabies rash Scabies mite in human skin (SEM)

Source: www. stanford.edu

Insects are Arthropods with Six Legs

Source: www. soton.ac.uk/~djab/ascaris.html

Tse-tse Fly: Host Vector ofAfrican Sleeping Sickness

Head Lice (Pediculosis)Head Lice (Pediculosis) Caused by a parasitic insect Caused by a parasitic insect Pediculus humanus capitisPediculus humanus capitis.. Transmission: Head-to-head contact or sharing personal Transmission: Head-to-head contact or sharing personal

items (clothing, brushes, towels). Most common in items (clothing, brushes, towels). Most common in children ages 3-11 and their families.children ages 3-11 and their families.

Symptoms: Tickling sensation on scalp, itching, Symptoms: Tickling sensation on scalp, itching, irritability, sores, and scratching. irritability, sores, and scratching.

Life StagesLife Stages Egg/Nit:Egg/Nit: Yellow or white, oval shaped, firmly attached to hair Yellow or white, oval shaped, firmly attached to hair

shaft. Females lay eggs near scalp (1/4 inch). Hatch in 8 to 9 days.shaft. Females lay eggs near scalp (1/4 inch). Hatch in 8 to 9 days.

Nymph:Nymph: Looks like a small louse and feeds on blood. Matures in Looks like a small louse and feeds on blood. Matures in

9 to 12 days.9 to 12 days.

Adult:Adult: Has six legs with claws, size of sesame seed, tan to gray Has six legs with claws, size of sesame seed, tan to gray

color. Feed on blood. Females can lay up to 100 eggs and live up color. Feed on blood. Females can lay up to 100 eggs and live up

to 30 days on head. Lice die within 1-2 days after falling off head.to 30 days on head. Lice die within 1-2 days after falling off head. Treatments: Fine tooth combs, chemical treatments, Treatments: Fine tooth combs, chemical treatments,

shaving hair, and hot air treatment (blow dryer device).shaving hair, and hot air treatment (blow dryer device).

Head Lice (Pediculus humanus capitis)

Egg/Nit, Nymph, and Adult Adult louse claws

Source: www. cdc.gov/NCIDOD/PARASITES/lice

Crustaceans are Arthropods with Four Antennae

Chapter 12: Fungi, Algae, Protozoa, and Parasites Fungi, Algae, Protozoa, and Parasites.

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Transcript of Chapter 12: Fungi, Algae, Protozoa, and Parasites Fungi, Algae, Protozoa, and Parasites.