Protista and FungiProtista and Fungi
Agents of Human Disease and Health
Features of fungiFeatures of fungi
• Eukaryotic and mostly multicellular
• Heterotrophic– digest food by secreting enzymes outside their
bodies, then absorb the digested nutrients
• reproduce sexually or asexually by spores
• decomposers help return nutrients to soil and air
Four Divisions of FungiFour Divisions of Fungi
1. Zygomycetes
• bread mold
• Some orders can
cause disease via
inhalation of spores by
immunocompromised
individuals
Four Divisions of FungiFour Divisions of Fungi
2. Ascomycetes
• yeasts, mildews, morels, truffles
• Some types can cause a type of athletes foot
Four Divisions of FungiFour Divisions of Fungi
3. Basidiomycetes
• common mushrooms
• Cryptococcus can cause meningitis in immunocompromised individuals
Four Divisions of FungiFour Divisions of Fungi
4. Deuteromycetes
• Roquefort cheese, athlete’s foot
Ecological and economic Ecological and economic importance of fungiimportance of fungi
• mycorrhizae were important in plant evolution• lichens important in soil formation, indicator of acid rain or air
quality• antibiotics – penicillin created with ascomycetes• cyclosporine - immune suppresser useful to transplant patients• Basidiomycota – decomposers that play a significant role in
the carbon cycle • Yeast necessary for bread production and are good genetic
engineering subjects
Kingdom ProtistaKingdom Protista
• mostly unicellular, some are multicellular (algae)
• can be heterotrophic or autotrophic
• most live in water (though some live in moist soil or even the human body)
• ALL are eukaryotic (have a nucleus)
• A protist is any organism that is not a plant, animal or fungus
3 Categories3 Categories
Grouped into three major, unofficial categories based on how they obtain nutrition
1.Protozoa - Animal-like Protists
2.Algae
3.Fungus-like Protists
ProtozoansProtozoans
Groups divided by type of locomotion • feed autotrophically as well as heterotrophically• most reproduce asexually
Zooflagellates - one or more flagella•Trypanosoma causes African sleeping sickness
Sarcodines - pseudopods
Ciliates – use cilia for feeding and movement
Sporozoans – parasites that do not move independently•Plasmodium causes malaria
AlgaeAlgae
•Photosynthesize but may become heterotophic in the absence of light•Live in fresh and salt water•Reproduce asexually
Euglenophytes – have two flagella but no cell wall
Chrysophytes – contain pectin instead of cellulose
Diatoms – cell walls are rich in silicon
Dinoflagellates – half photosynthesize, half heterotrophic–Gonyolax – toxin causing red tides which causes paralytic shellfish poisoning when is makes humans sick
•
Fungus Like ProtistsFungus Like Protists
• Heterotrophs that decay organic matter
• Have centrioles but lack chitin unlike true fungi
Slime Molds – recycle organic matter
Water Molds – live on dead matter in water; some are plant parasites on land
• Phytophthora infestans – type of water mold that caused the Irish potato famine between 1845 and 1851