Protists Three Groups of Protists Animallike Protists Plantlike

Protists Three Groups of Protists: Animal-like Protists Plant-like Protists Fungus-like Protists

Protist Diversity l 200, 000 species: different shapes, sizes, and colors l All eukaryotes – have a nucleus and membrane-bound organelles l Not bacteria, animals, plants, fungi (the organism junk drawer) l Reproduce asexually or sexually

Protists are the most diverse of all eukaryotes.

Asexual reproduction Binary l fission l

Sexual reproduction l Conjucation

Animal-like Protists “Protozoa”

Protozoans l Unicellular –one cell l Heterotrophs – they eat other organisms or dead organic matter l Classified by how they move

Phyla of Protozoans Phylum Zoomastigina “Zooflagellates” (giardia) Phylum Sarcodina“Sarcodines” (amoeba) Phylum Ciliophora “Ciliates” (paramecium) Phylum Sporozoa “Sporazoans” (plasmodidium)

l Sarcodines – move by extensions of their cytoplasm. l Ciliates – move by means of cilia. l Sporozoans – do not move on their own.

Amoebas: the blobs l No cell wall l Move using pseudopods – plasma extensions l Engulf bits of food by flowing around and over them

Amoeba Pseudopods Found in freshwater Moves using pseudopods- “false feet”cytoplasmic projections

They also use pseudopods for feeding Amoeba Pseudopod Paramecium Pseudopod Food Vacuole

More amoebas

l Amoebic dysentery Entamoeba histolytica l Amoebas feed on intestinal lining, causing bloody diarrhea. l Contaminated food or water. l

Flagellates: the motorboats l Use a whip-like extension called a flagella to move l Some cause diseases

l Giardiasis – Giardia lamblia Cramps, nausea, diarrhea, and vomiting l Contaminated water l Leishmaniasis – Trypanosoma Skin sores and deep, eroding lesions. Bites from sand flies.

l Trichomonas foetus : cow disease

l Trichomonas vaginalis: an STD

Ciliates: the hairy ones l Move beating tiny hairs called cilia

Paramecium- move using cilia (tiny hairlike projections)

Paramecium reproduction

Sporazoans: the parasite l Non-motile - Do not move l Live inside a host l One type causes malaria

l Malaria in red blood cells

l MALARIA – Plasmodium Causes severe chills, fever, sweating, confusion, and great thirst. l Spread from person to person by the anopheles mosquito. l

Plant-like Protists “Algae” The Unicellular

Plant-Like Protists

What are Algae? l Unicellular – made of one cell l Multicellular – made of more than one cell l Photosynthetic – make their own food l No roots, stems, or leaves l Each has chlorophyll and other photosynthetic pigments

Red algeal bloom Brown Algea: Giant Kelp Forest Volvox: a green colonial algae

Phyla of Unicellular Algae Phylum Euglenophyta (euglena) Phylum Chrysophyta (golden algae) Phylum Bacillariophyta (diatoms) Phylum Pyrrophyta (dinoflagellates)

Euglenoids: l Aquatic l Move around like animals l Can ingest food from surroundings when light is not available

Euglena l l Euglena contain: chloroplasts, a flagella, and an eyespot to sense where light is. Unique because they are both heterotrophic and autotrophic.

Diatoms: The Golden Ones l Have shells made of silica (glass) l Photosynthetic pigment called carotenoids – give them a golden color

Dinoflagellates: The Spinning Ones l Spin around using two flagella l Responsible for Red Tides l Create toxins that can kill animals and sometimes people

l High Algal Blooms temps and increase in nutrients (nitrates and phosphates) lead to increased algae populations l Harmful to fish and humans (red tide)

Swimming with Bioluminescent Dinoflagellates

Plant-like Protists “Algae” The Multicellular

Plant-like Protists l l All are autotrophic-meaning they can make their own food Examples: Euglena Algae

Phyla of Multicellular Algae Phylum Rhodophyta (Red Algae) Phylum Phaeophyta (Brown Algae) Phylum Chlorohyta (Green Algae)

Red Algae: l Seaweeds l Multicellular, marine organisms l Have red and blue pigments

Brown Algae: l They have air bladders to help them float at the surface – where the light is.

Green Algae: l Most live in fresh water l Can be unicellular or multicellular l Live alone or in groups called colonies

Green Algae: l Unicellular l Colonial – Chalamydomonas Algae – spyrogyra, volvox l Multicelluar - Ulva

Conjugation of Spyrogyra

The life cycle of Chlamydomonas

“cloning” – plants identical to each other Isogamy = male and female gamete identical in size Sexual reproductioncreate variation

Fungus-like Protists

Fungus-Like Protists

Fungus-like Protists l All form delicate, netlike structures on the surface of their food source l Obtain energy by decomposing organic material

Phyla of Fungus-like Protists Phylum Acrasiomycota - Cellular Slime Molds Phylum Myxomycota - Plasmodium Slime Molds Phylum Oomycota - Water Molds & Downy Mildews

Slime Molds l Live in cool moist, shady places where they grow on damp, organic matter

Plasmodium Slime Molds l Form plasmodium: a mass of cytoplasm that contains many diploid nuclei but no cell walls or membranes – its feeding stage l Creeps by amoeboid movement – 2. 5 cm/hour

Plasmodium continued… l May reach more than a meter in diameter l Form reproductive structures when surroundings dry up l Spores are dispersed by the wind and grow into new plasmodium

Cellular Slime Molds l In feeding mode, they exist as individual amoebic cells l When food becomes scarce, they come together with thousands of their own kind to reproduce l May look like a plasmodium

Slime molds upclose Water and Slime molds are not in the Kingdom Fungi because their cell walls are made up of cellulose not chitin.

Figure 27. 32 A Cellular Slime Mold

Figure 27. 14 Alternation of Generations The standard or beginning model

Water Molds and Downy Mildews l Live in water or moist places l Feed on dead organisms or parasitize plants l Fuzzy white growths

Water molds: l l l Completely aquatic Often decomposers Sometimes parasitic Water mold attacking a fish