PROTISTS

PROTISTS COMMON EXAMPLES: Amoeba, paramecium, euglena, volvox, plasmodium EUKARYOTIC –Have a nuclear membrane VERY DIVERSE GROUP –most are unicellular, microscopic, aerobic –Some are autotrophic, heterotrophic, sexual, asexual

PROTISTS PROTIST CLASSFICATION –Separated by feeding habits (nutrition) –Autotrophic Able to make own food –Heterotrophic Must eat other material Unicellular May be predators, decomposers, or parasites

PROTISTS REPRODUCTION –Asexual Mitosis and cytokinesis Budding – similar to mitosis except daughter cell is smaller than parent –SEXUALLY Conjugation – exchange of nuclear material between two individuals

PROTISTS ANIMAL LIKE PROTISTS = PROTOZOA –Classified by method of movement PLANT LIKE PROTISTS = ALGAE –Classified by pigment color FUNGUS LIKE PROTISTS = MOLDS –Classified by body form

PROTISTS PROTOZOA –Heterotrophic –Unicellular –4 groups SarcodiniansZooflagellatesCiliatesSporozoans

PROTISTS ENDOSYMBIONT THEORY –Early eukaryotes developed symbiotic relationships with prokaryotic cells –Prokaryotic cells lived inside eukaryotic cells –Over time, the smaller prokaryotic cells evolved with the eukaryotic cells to become mitochondria and chloroplasts

PROTISTS EXCRETION AND OSMOREGULATION –Water balance = osmoregulation –Done by contractile vacuole –Wastes removed by diffusion RESPIRATION –Carbon dioxide and oxygen diffuse in and out

PROTISTS –SEXUALLY Conjugation – exchange of nuclear material between two individuals

PROTISTS DOMAIN EUKARYOTA –KINGDOM PROTISTA Any eukaryote that is not classified as a fungus, plant, or animal is a PROTIST

PROTISTS SARCODINES SARCODINES –Aquatic, clear cytoplasm, irregular shape –Move by extending lobes of their cytoplasm –Pseudopods (false feet) –Nucleus, contractile vacuole, food vacuole –Example: Amoeba

PROTIST

PROTIST SEE PAGE 537 TO LABEL THIS AMEOBA

PROTISTS ZOOFLAGELLATES –Often called flagellates because they move using flagella (Whip-like tail) –Absorb food by diffusion through cell membrane –Live off of dead or decaying organic matter or some are parasites: feed off host –Helpful:helps termite digest wood –Harmful: Cause African sleeping sickness

PROTISTS

PROTISTS CILIATES –found in fresh and salt water, most are larger than other protozoa –Move using small hairs called cilia –Pellicle, cilia, food vacuole, contractile vacuole –Small nucleus (exchanged during conjugation) –Big nucleus (controls daily functions)

PROTISTS –Oral groove – shallow furrow on one side of cell used to gather food –Locomotion – cilia; avoiding reaction  contact with unfavorable conditions and will move away

PROTISTS –Example = paramecium

PROTIST

PROTISTS SPOROZOA –Members cannot move –Reproduce by producing spores –Parasites –Example: Plasmodium – causes malaria; carried by mosquito

PROTISTS

PROTISTS PLANT LIKE PROTISTS –Most perform photosynthesis –Contain chlorophyll in chloroplast –Divided into groups by pigment color EUGLENADINOFLAGELLATADIATOMS

PROTISTS –Movement toward light using flagella; flagella pulls cell; euglenoid movement  expansion and contractions of entire cell –Nutrition – can capture food; can absorb nutrients from water or carry on photosynthesis –Reproduction – mitosis; form cyst during harsh times

PROTIST EUGLENA –Usually free-living (not a parasite) –Pellicle – covering membrane; maintains shape –Cell mouth, gullet, reservoir (holds flagella), contractile vacuole, food vacuole –Stigma (eyespot) - light sensitive –Nucleus, chloroplasts

PROTISTS

PROTISTS GREEN ALGAE –Contain chlorophyll –Some reproduce sexually –Examples: desmids, spirogyra –Most live in fresh water or moist soil –Many live in symbiotic relationships Lichen – organism composed of an algae and a fungi living together as one

PROTISTS

PROTISTS

PROTISTS

PROTISTS RED ALGAE –Grow in warm salt water habitats – toward surface or deep water –Perform photosynthesis –Example: Red moss

PROTISTS BROWN ALGAE –Multicellular and live in cool salt water habitats –Includes giant kelps –Have an alternation of generations life cycle (means that part of life is spent reproducing asexually and part is spent reproducing sexually)

PROTISTS Used to make a variety of products As a thickening agent in puddings, ice cream Used as food for animals (processed)

PROTISTS DIATOMS – –Some species are colorless, but most are photosynthetic. –important in lakes, where they may be the primary source of food for zooplankton. –not truly autotrophic because most become heterotrophic in the absence of light, or in the presence of plenty of dissolved food. –Used in toothpaste

PROTISTS DINOFLAGELLATA DINOFLAGELLATA –Nearly all have flagella –Most grow in salt water –Most are free-living (meaning they are not parasites); some have symbiotic relationships with other organisms –When agitated undergo reaction that produces light  bioluminescent –Cause Red Tide

PROTISTS DINOFLAGELLATE

PROTISTS

PROTISTS –Cause the red tide –Several microscopic marine algae are notoriously poisonous to hapless humans who consume them in shellfish. –some species are poisonous to animals which feed upon them directly or indirectly. Some of the toxins these species produce are seriously toxic. Often, the algae themselves are unaffected, as are the filter feeders, especially shellfish, for whom micro-algae are the principal diet. However, to carnivores further up the food chain, including humans, these toxins are potentially FATAL.

PROTISTS FUNGUS-LIKE PROTISTS (MOLDS) –CHARACTERISTICS MOST ARE SMALL AND LIVE IN DAMP PLACES PROTISTS THAT ACT AS DECOMPOSERS ARE CALLED MOLDS DIVIDED INTO 3 GROUPS –PLASMODIAL SLIME MOLDS –CELLULAR SLIME MOLDS –WATER MOLDS

PROTISTS PLASMODIAL SLIME MOLDS –Can weigh as much as 50 grams and be as large as a human hand (one cell!) –Single cell with many nuclei –In unfavorable conditions Moves somewhere else Creates a fruiting body

Myxomycota - plasmodium

PROTISTS CELLULAR SLIME MOLDS –ALTERNATES BETWEEN A SPORE PRODUCING FRUITING BODY FORM AND AN AMEBALIKE FEEDING FORM –SINGLE CELLS UNITE TO FORM ONE LARGE MASS WHEN TIMES ARE HARSH

The phyla of slime molds:

PROTISTS WATER MOLDS –DECOMPOSERS IN FRESHWATER ECOSYSTEMS –SOME ARE PARASITIC

PROTISTS IMPORTANCE OF PROTISTS –ECOLOGICAL ROLES Provide an essential food base in aquatic food chains Carry out more than 30-40% of Earth’s photosynthesis Protozoans help keep the number of bacteria in check