The most diverse group of organisms Kingdom Protista The most diverse group of organisms

Discovery of Protists Anton van Leeuwenhoek Lived around 300 years ago First to use a microscope to see cells “No more pleasant sight has met my eye than this of so many thousands of living creatures in one small drop of water.”

What can you find in a single drop of water??

Evolution of Protists Evolved from prokaryotes 1.5 billion years ago Protists are the first known eukaryotic organisms They would lead to the evolution of fungi, plants and animals

What is a protist? A eukaryote that cannot be classified as fungi, plant or animal An organism that has very diverse characteristics A microscopic organism that lives in water Can be grouped into two general categories: Protozoa Algae

How many cells?? (It depends!) Most protists are unicellular, but some are multicellular Some are colonial each individual has a specific number of cells all individuals together make up the colony the colony acts like a multi-celled organism

Volvox Colonies http://video.google.com/videoplay?docid=-3471807967695834419

What is their function? (It depends!) Some are… Producers many protists are photosynthetic and are major contributors to the Earth’s oxygen atmosphere Consumers some protists eat other organisms for energy Decomposers some breakdown dead organisms to return nutrients to the soil

The Protozoa Blues http://video.google.com/videoplay?docid=3578205676570425677&q=protozoa+site%3Avideo.google.com&total=13&start=0&num=10&so=0&type=search&plindex=2

Protists: The 411 All are Eukaryotes All are aerobic (require oxygen) All have mitochondria All live in water-based environments (fresh water, oceans and seas, damp soil, snow) Some have chloroplasts Some reproduce asexually, some sexually

3 Main Types Plant-like protists Animal-like protists Fungus-like protists

Plant-like Protists (AKA algae) Algae are protists that are strictly photosynthetic Algae are distinguished by the type of photosynthetic pigment they contain Algae are also classified based on their cell or body shape

Green Algae – Phylum Chlorophyta Most are found in freshwater Major part of plankton (small organisms found on the surface of a body of water) Contain chloroplasts and undergo photosynthesis Green Algae – Phylum Chlorophyta Biscayne Bay – Miami, FL

Brown Algae – Phylum Phaeophyta Multicellular Found in marine and coastal regions Examples: kelp, seaweed Can be up to 30 m long Provide protection and shelter for many coastal fish

Red Algae – Phylum Rhodophyta Caloosahatchee River, SE Florida (Gulf of Mexico side of Florida) Red Algae – Phylum Rhodophyta Multicellular Found in tropical zones and deep ocean regions Able to absorb light that penetrates deep waters

Diatoms – Phylum Bacillariophyta Unicellular Cell wall contains silica (mineral found in glass) Double shell (fits together like the bottom and top of a shoe box) Their shells are used to make reflective paints Diatoms – Phylum Bacillariophyta

Dinoflagellates – Phylum Dinoflagellata Have 2 flagella Huge increases in population cause red tides = fish are killed due to less oxygen in the water, water looks red due to overpopulation Most are found in saltwater

Euglenoids – Phylum Euglenophyta One flagella Eyespot – light sensitive organ that tells the organism to move toward light Found mostly in freshwater

Animal-like Protists (AKA protozoa) Classified based on their type of nutrition Ingest their food by endocytosis (engulfing food into the cytoplasm)

Paramecium – Phylum Ciliophora Move by beating tiny hair-like structures called cilia The cilia act in unison like oars on a boat Have one large contractile vacuole for water and waste storage

Amoebas – Phylum Rhizopoda Move by pseudopodia (false feet) Amoebas can live in water, soil or living organisms Amoebas – Phylum Rhizopoda

Sporozoans – Phylum Apicomplexa All parasites Transmitted through blood-eating insects or feces Sporozoans – Phylum Apicomplexa

Malaria One of the most deadly diseases in humans Caused by a protist called plasmodium A mosquito bites an individual and the protist is injected into the blood stream Over 100 million people have malaria Up to 3 million people, mostly children, die from it every year

Symptoms include severe chills, fever, sweating, and confusion Victims typically die of other related complications including anemia, kidney failure or brain damage Malaria and fake drugs: http://video.google.com/videoplay?docid=8997083794746163547&q=malaria&total=1547&start=0&num=10&so=0&type=search&plindex=3 (first 10 minutes)

Fungus-like Protists (AKA molds) Two groups Plasmodial slime molds Phylum Myxomycota Look like oozing slime Absorb bacteria and nutrients as they slowly move Water molds Phylum Oomycota Usually feed on dead material Responsible for the potato famine in Ireland (1845-1850) that killed almost 1 million people