Chapter 25 Protists

Protists 1 Chapter 25 Kingdom Protista I

Nature of Protists A) Eukaryotes B) Unicellular C) Aquatic D) Some autotrophs, some heterotrophs E) Reproduction: binary fission, conjugation.

II Subkingdom Protophyta → Algal Protists. A) Many called algea B) Plant-like, contain chlorophyll C) Three phyla: 1) Euglenophyla EX: euglena 2) Chrysophyta EX: diatoms 3) Pyrophyla EX: dinoflagellates D) Euglenophyta (euglenoids) 1) Both plant and animal characteristics 2) Found in fresh H2O 3) Contain chloroplasts 4) Can move (a)By changing its shape (b)By flagella – 1 whip like tail 5) Contractile vacuole: regulates H2O balance 6) Eyespot – red, sensitive to light

Protists 2 7) Also heterotrophs; when deprived of light euglena absorb nutrients through cell membrane. III Phylum Chyrosophyta (EX: Diatoms) A) Autotrophic B) Body is covered by a 2 part shell or call wall made of silica (glass) IV Phylum Pyrrophyta EX: Dinoflagellates A) Autotrophic B) 2 flagella for movement C) Have RED pigments for color D) Causes: 1) Red tide: a condition where the oceans become red because many dinoflagellates release their poisons (red). (a)Poisons build up and kill the fish V Subkingdom (protozoans) animal-like A) Classified according to their method of locomotion B) Heterotrophs C) 4 phylums: 1) Sarcodina EX: ameoba 2) Ciliata EX: paramecium 3) Sporozoa EX: plasmodia 4) Mastigophora EX: flagellates D) Phylum – Sarcodina EX: amoeba 1) Move by finger like extensions called pseudopodia for locomotion and engulfing prey. 2) Found in freshwater 3) Cytoplasm – 2 regions

Protists 3 (a)Ectoplasm: clear outer layer just inside cell membrane (b)Endoplasm: granular inner cytoplasm with organelles. E) Other sarcodines: 1) Radiolarian: silica (glass) shell with needle-like pseudopodia 2) Foraminiferan: calcium carbonate(limestone) shell – pseudopodia from small holes F) Diseases 1) Amoedic dysertary: amoeba enters man by contaminated H2O/vegetables, from human feces (a)You get 40-50 dihareed a day VI Phylum Ciliata EX: paramecium A) Body: slipper shaped B) Body covered by tiny, short hairs → cilia C) 2 nuclei 1) Macronucleus: controls all (large) 2) Micronucleus: contains DNA for reproduction (small) D) To catch preyor for defense they release richosis (like arrows) VII Phylum Mastigophora A) Have a flagella – long whiptail for movement B) Many are parasitic and cause disease C) Diseases 1) African sleeping sickness (a)Fly bites and infects man or animal. Parasite goes to the brain and toxins build up – extreme desire for sleep – die.

Protists 4 VIIIPhylum Sporozoans EX: Plasmodia A) No external structures for movement so they are parasitic in a host. B) Unusual – each protist produces many nuclei C) Have complex life cycles involving one or more hosts D) Diseases 1) Texas fever: caused by a plasmodium carried by ticks 2) Malaria: plasmodium lives in a mosquito. Mosquito bites a person and infects them with the parasite (protists). Destroys red blood cells.