What is a Protist?
unicellular or multicellular
anything except plants, animals, or fungi
65,000 species
Autotrophs, heterotrophs, or both
What is a Protist?
classified according to the way they move
Found in freshwater, marine, and moist habitats
many are free living but some are parasitic
Protist Reproduction
1. binary fission (mitosis) - Amoeba
2. Conjugation – like bacteria
3. Some produce spores
Protist Classification
4 phyla based on movement
1. Sarcodina2. Ciliophora3. Zoomastigina4. Sporozoa
Phylum Sarcodina called sarcodines
Move and obtain food by pseudopods (false foot)
Found in freshwater, marine, & moist soil habitats
reproduce by binary fission
No definite shape
EX. Amoeba
Brain-Eating Amoeba
Amoeba Video
Phylum Sarcodina
Paramecium Video
Phylum Ciliphora
Largest group; called ciliates
Move by cilia
Cilia short hairlike projections used to move, get food, and senses
Mostly freshwater; some marine
Phylum Ciliphora
Eating – sweep food into their gullet
Reproduce by binary fission or conjugation
Paramecium
Phylum Zoomastigina
Called zooflagellates
Move by flagella
Freshwater or marine
Usually live inside other organisms –contaminated water
Phylum Zoomastigina
Some are parasites –trypanosome, causes African sleeping sickness
Spread by the bite of the tsetse fly
Phylum Zoomastigina
some are mutalistic
Mutalistic—> both organisms benefit
Trichonympha lives inside termites & digests cellulose
Phylum Sporozoa
Called sporozoans -parasites
Form spores –reproductive structure
Don’t move; carried from one host to another
Live in the body fluids of hosts
Plant like Protists
Used to make a variety of products
As a thickening agent in puddings, ice cream
Used as food for animals (processed)
Diatoms
Important food source in oceans
Shells are made of silica –used to make glass
Form diatomaceous earth - abrasive
Dinoflagellates
90% marine
photosynthetic
Bioluminescence – produce light
Poisonous red tides which can be harmful to shellfish
Fungus like Protists
Heterotrophs Reproduce by spores decomposers Not a fungus because
they can move at some point
EX. slime mold and water molds (potato and tomato blight)
Importance of Plantlike protists
Photosynthetic protists form the base of the food chain for much aquatic life.
Carry out approximately 50% of photosynthesis on earth
Feed fish and whales – phytoplankton
Support coral reefs
Provide shelter – kelp
Recycle wastes but can produce algal blooms (red tide)
Protist Diseases
African Sleeping Sickness Caused Trypanosomes Spread and carried by a tsetse fly
Trypanosomes attack the blood and nerve cells
Person loses consciousness and laps into a deep and sometimes fatal sleep
Endemic to sub-Saharan Africa
Protist Diseases
Amoebic Dysentery
caused by an Entamoeba
Spread by poor sanitation
Causes intestinal bleeding and severe diarrhea
Protist Diseases
Giardiasis
Caused by Giardia
Causes severe digestive problems and severe diarrhea
1980s – outbreak in NEPA.
Protist Diseases
Malaria
Most serious
1 million die each year; #1 killer 1,300 cases are diagnosed in US each
year
Protist Diseases
Malaria
Caused by the sporozoan Plasmodium
Carried by the female Anophelesmosquito
Africa, child dies every 30 seconds from malaria
What is a Fungus?
multicellular heterotrophs
live on dead organisms - saprophyte
Digest food outside of their bodies
decompose and recycle nutrients
Grow in warm, moist environments
yeast, mushrooms, and molds
Fungus Parts1. Hyphae thin cells of a fungus Grow into food and secrete digestive
chemicals into it2. Mycelium many hyphae tangled
together – the body
3. Fruiting body part that you see growing from the soil
Reproductive structure -contains the spores
Fungus Reproduction
Can reproduce asexually – spores or budding
Also reproduce sexually
Spores can be dispersed mostly by wind, but also by rain drops, animals, insects, water
Ecology of Fungus
1. Decomposition break down leaves, fruit, and organic matter
2. Parasites cause plant and animal disease
Fungal Diseases
Many are harmless and easy to treat
Fusarium keratitis serious fungal infection of the cornea
Fungal Diseases
Ringworm affects the skin; usually the scalp
Athelete’s foot tinea infection between the toes