Kingdom Protista

Characteristics of Kingdom Protista Very diverse. Eukaryotic. Mostly unicellular. Appeared about 1.5 bya. Formed by endosymbiosis.

Classification of Protists Animal like protists Zooflagellates Sarcodines Ciliates Sporozoans

Classification of Protists Plant Like Protists Unicellular Euglenophytes Chrysophytes Diatoms Dinoflagellates Multicellular Red Algae Green Algae Brown Algae

Classification, con’t Fungus like Protists Slime molds Water molds

Zooflagellates Swim using flagella. Absorb food through cell membrane. Asexual (most) and sexual (some).

Sarcodines Click to See Amoeba in Motion Move and eat by PSEUDOPODIA – false feet – cytoplasm projections. Ameobas are best known. Form food vacuoles. Reproduce by mitosis and cytokinesis. Foramnifera – secrete shells of CaCO3 White Cliffs of Dover

Ciliates Move with hair like projections called cilia. Click to see stalked ciliate Move with hair like projections called cilia. Also use cilia for feeding – sweep food particles into the gullet which are then incorporated into food vacuoles. Use trichocysts for defense. Contractile vacuole – a way to maintain homeostasis. Macronuclei and micronuclei. Reproduce by conjugation and then mitosis. Click to compare flagella and cilia http://upsidedownhippo.com/archives/2005/07/index.html

Sporozoans Do not move on their own. Parasitic. Complex life cycles. Malaria has a vector – Anopheles mosquito. Plasmodium – a sporozoan in Blood – causes MALARIA

Other Protozoa Diseases Trypanosome – African Sleeping Sickness, a zooflagellate – vector is tsetse fly. Amoeba (sarcodine)– dysentery – Giardia, Entamoeba.

The Good Guys Click here to see trichonympha Trichonympha – lives in gut of termite – digests cellulose into glucose

Plant Like Protists Euglena. Unicellular. No cell wall. Click Here to see a Euglena Party Euglena. Unicellular. No cell wall. Live as autotrophs in light, as heterotrophs in dark. Eyespot helps find light. Pellicle – fancy cell membrane. Reproduce by binary fission.

Chrysophytes Golden Algae. Unicellular. Store food as oil rather than starch. Sexual and asexual.

Diatoms - Bacillariophyta Unicellular. Cell walls rich in silicon. Two pieces like a petri dish.

Pyrrophyta - Dinoflagellates Unicellular. Some autotrophic, some heterotrophic. Can luminesce. Enormous growth called algal bloom – Red Tides – produce toxins.

Ecology Plantlike protists common in fresh and saltwater. 50% of photosynthesis on Earth from phytoplankton. Important in ecosystems because they are the base of food chain. Algae Blooms can deplete resources and disrupt equilibrium.

The Algaes Red, Brown and Green. Most are multicellular. Have different proportions of chlorophylls. Brown Algaes are the giant kelps (Example: Sargassum). Red Algaes important in coral reefs. Green algae most like plants- found all over – fresh and salt water. Cell walls of cellulose. Same chlorophyll as plants. Store food as starch.

Algae

Reproduction – Green Algae

Human Uses of Algae FOOD Treating ulcers, high blood pressure, arthritis. Seaweed wrapping for sushi. Algal products used in ice cream, pudding, salad dressing, candy bars, pancake syrup, eggnog… Chemicals from algae used to make plastics, paints, waxes, deodorants... Agar for growing bacteria derived from seaweed.

Fungus like Protists Slime molds Click to see slime mold Like fungi, slime molds absorb nutrients from dead/decaying matter Some have stages with large multi-nucleated cells formed from by cells fusing together.