protists michelle reilly, cady trvalik and lisa lucero
TRANSCRIPT
Protists
Michelle Reilly, Cady Trvalik and Lisa Lucero
The Six Groups
Euglenozoa
Alveolata
Choanoflagella Brown Algae (Stramenopila)
Rhodophytakinetoplastid (Euglenozoa).
Chlorophyta
Stramenopila
All protists are aquatic - a few are terrestrial.
Three Types of ProtistsAnimal-like - protozoans• all heterotrophic, unicellular and mobile.
o divided by mobility/means of attaining food: pseudopods cilia flagella parasites
Fungi-like • all heterotrophic• contain long hyphae- like strands (bright in color)• can act as decomposers - break down dead organisms by releasing digestive
enzymes into organism.
Plant-like - all algae-Autotrophic capable of making their own food-contain chlorophyll and carry out photosynthesis-commonly called algae-four phyla: euglenophytes, chrysophytes, diatoms, dinoflagellates-accessory pigments help absorb light, give algae a variety of colors
Anatomy of a ProtistExtreme diversty: most cells contain:• nucleus or macronucleus: where the DNA is contained• micronuclei: smaller storages of DNA for everyday use.• cell membrane: pellicle, specialized to protists• cell walls: in plant-like protists• gullet: indentation on side of protist where food is swept• vacuoles: "bubbles" in cytoplasm to store/digest food • eyespot: helps protist to find light. • capsule: extra membrane.
Remember that the anatomy of a protist varies on whether it is animal-like, plant-like or fungus-like.
Digestion
Differs based on group:• Animal-like: heterotrophic
o use cilia, flagella and pseudopods to engulf food
o phagocytosis o vacuoles
• Fungus-like: heterotrophico phagocytosis of bacteria
• Plant-like: autotrophico photosynthesis o metabolic pathways plant-likeo chlorophyll A and C - not much B - and carotenoids
Excretion
• Excretion o excretion - the process of removing metabolic wastes
• Special excretory structures are absent in many unicellular organisms. o Excretion is accomplished by diffusion through cell membranes
• Freshwater Protozoans- in the amoeba and paramecium CO2, ammonia, and mineral salts diffuse through the cell membrane directly into the aquatic environment.
• Contractile vacuoles and osmosiso Contractile vacuole - pumps excess water out of the cell.o osmosis - the tendency of a fluid, usually water, to diffuse from
an area of high to low concentration.
Gas Exchange
• takes place directly at membrane - diffusiono diffiusion: unfacilitated movement of objects across a
membrane from area of high to low concentration• do not need specialized respiratory system
o autotrophs take in CO2, give off O2o heterotrophs take in O2, give off CO2
• diffusion keeps protists small - disadvantage
Circulation
• circulation- movement of materials within a cell or between parts of an organismo no circulatory system is needed for protists
• protists have a thin cell membrane • absorption occurs by diffusion & active transport
o active transport - the movement of ions or molecules across a cellular membrane from a lower to a higher concentration, requiring the consumption of energy.
• circulation occurs by cylosiso movement of cytoplasm
ReproductionGreat variation - most common in red.• Animal-like:
o asexual: binary/multiple fission, budding, encystmento sexual: isogamy, anisogamy, oogamy.
• Plant-like: o primarily asexual: binary fission, sporogony
• Fungus-like: o primarily sporogony, some binary fission
Plant and fungus-like protists often undergo an alteration of generations.
Support and Movement of Protist
Cilia-Used for movement-Hair like projections -May completely cover cell surface or may be clustered in a few rows or tufts-When bonded together can construct "leg-like" structures
Flagella -Long cellular for locomotion-Used for movement-"Hairy" numerous fine, hairlike projectionsvs. "Smooth" flagella
Lifestyle and Environment of a Protist
-They live in almost any environment that contains liquid water-Protist such as algae, are photosynthetic and are vital primary producers in ecosystems-Play big role in the ocean as part of the plankton-Healthy levels of algae will provide much of the oxygen for various animals-Algae are a food source small animals that live in water.-Diatoms may produce oxygen in our atmosphere-Amoeba, form the ‘predator’ stratum of the food chain-Many protozoans are parasitic on humans and our livestock-Some cause diseases such as malaria
Animal-like Protist: Paramecium
• covered with cilia - aid in motion and feeding• Dinidium: a Paramecium's worst nightmare• trychocists used for defense, hunting.• devoid of senses - can sense motion and do 360-degree turns• live in warm, stagnant water• reproduce sexually and asexually• can use electromagnetic radiation, biophotons, to
communicate
Fungi-like Protist : Slime Molds
• lives in moist soil, decaying plants, and trees.
• very bright appearance • single- celled organisms• go from single-celled to
unicellular, back to single-celled
• Form sporangiao sporangia - a cluster of
cells on top of a stalk
Plant-Like Protist: Euglena-contain chlorophyll and carry out photosynthesis-commonly called algae-four phyla: euglenophytes, chrysophytes, diatoms, dinoflagellates-accessory pigments help absorb light, give algae a variety of colors
-live in water-have 2 flagella for movement-use chlorplasts for photosynthesis, but can turn into heterotrophs if they are kept in the dark-has an eyespot used for sensing light and dark -pellicle - like a cell wall, helps maintain their shapes
Works Cited"Excretion." Onteora Central School District. Web. 07 Nov. 2011. <http://onteora.schoolwires.com/4370_71121142518 /lib/4370_71121142518/excretion.html>. "Kingdom Protista." Phylogeny Project. Web. 07 Nov. 2011. <http://evanphylogenyproject.blogspot.com/2011/01/kingdom- protista.html>. "Mr. Carl's E-Class on Protists." Lanesville Community School Corporation. Web. 07 Nov. 2011. <http://lanesville.k12.in.us /LCSYellowpages/Tickit/Carl/protists.html>. "Paramecium." Learn Science Electronics Biology Chemistry Physics. Web. 07 Nov. 2011. <http://101science.com /paramecium.htm>. "Protist (biology) -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. Web. 07 Nov. 2011. <http://www.britannica.com/EBchecked/topic/480085/protist>. "Protista." Biology at Clermont College - University of Cincinnati. Web. 07 Nov. 2011. <http://biology.clc.uc.edu/courses/bio106 /protista.htm>. "Protista Group." NCWC: Student Pages. Web. 07 Nov. 2011. <http://students.ncwc.edu/bio101/protista/Default.htm>. "Protista Group." NCWC: Student Pages. Web. 07 Nov. 2011. <http://students.ncwc.edu/bio101/protista/Default.htm>. "Protists - Definition, Types, Structure." Biology Questions. Web. 07 Nov. 2011. <http://www.biology-questions-and-answers.com /protists.html>. "Protists II: Algae and Fungus-like Protists." Christian Brothers University. Web. 07 Nov. 2011. <http://www.cbu.edu/~seisen /ProtistsII.htm>. "Respiratory System." Onteora Central School District. Web. 07 Nov. 2011. <http://onteora.schoolwires.com/4370_71121142518 /lib/4370_71121142518/gasexchange.html>. "Transport." Onteora Central School District. Web. 07 Nov. 2011. <http://onteora.schoolwires.com/4370_71121142518 /lib/4370_71121142518/transport.html>.