Protists• The most diverse kingdom of eukaryotes• All are eukaryoteseukaryotes – have a nucleus and

membrane-bound organelles• Protists often have a very complicated internal

structure: a single cell must do all the functions that we have many different cell types to do.

Protists are the most diverse of all eukaryotes.

How are Protists classified?

• Mode of nutrition is used to classify protists into 3 main groups– Protozoa (ingestive, animal-like)– Algae (photosynthetic, plant-like)– Slime molds (absorptive, fungus-like)

Protozoan are classified by how they move

• Pseudopodia

• Cilia

• Flagella

• Non-moving on their own: spores

Rhizopods (like the Amoeba) move with psuedopods

http://shs.westport.k12.ct.us/mjvl/biology/cells/amoeba.gif

•This drawing of an amoeba illustrates the pseudopod.

• Can you recognize the pseudopod in this amoeba?

More Rhizopods: Note the psdeudopods

• Heliozoans

• Radiolarians

• Foraminiferans

Protozoans

• Trypanosoma --------- is the protozoan that causes African sleeping sickness

• Giardia ------------------ causes the diarrhea sickness contracted from contaminated water (yuck! – always bring your own water on hikes!)

www.innovations-report.com/. ../report-19279.html martin.parasitology.mcgill.ca/.../ GIARDIA.HTM

Sporozoans – live inside hosts

parasitol.wkhc.ac.kr/ image/oth/mosq.GIF

•These protozoans may seem harmless since they can’t move on their own, but they use vectors, such as insects, to get them where they want to go.

•Plasmodium (purple in a field of red blood cells) is the protozoan that causes malaria with the help of mosquitoes as the vector.

Paramecium – move with cilia

A common protozoan is the paramecium – can you see the cilia?

http://faculty.plattsburgh.edu/jose.deondarza/research/Photos/Paramecium.jpg

Cilliates

Stentor

Stentor

Now that you are a protozoan pro, do you remember the next group of protists – those that

make their own food?

ALGAEALGAEClick to see the correct answer…

Algae

There are 6 main phyla of these plant-like protists:

1. Green algae2. Euglena3. Dinoflagellates4. Diatoms5. Red algae6. Brown algae

Let’s take a look…

Green algae: they are green!!

www.sonoma.edu/biology/ algae/Green.html www.acadweb.wwu.edu/.../ 25_hydrodictyon_40x.jpg http://www.acadweb.wwu.edu/courses/envr429-rm/Robin/images/envr429/27_oedogonium_40x.jpg

•Green algae are thought to be the direct ancestor of land plants

Colonizing algae - Volvox

Volvox

Euglena

http://www.bgbm.org/kusber/images/euglena.gif

The euglena performs photosynthesis like a plant, but has a flagellum and moves around like a protozoan.

http://www.cartage.org.lb/en/themes/Sciences/BotanicalSciences/MajorDivisions/KingdomProtista/Protists/euglena.gif

Dinoflagellates

• have 2 flagella that make them spin; some can secrete dangerous toxins – one example is the red tides caused by Pfiesteria, which lead to fish kills

http://biology.nebrwesleyan.edu/Courses/Labs/Biology_of_Animals/ZooLab9/Dinoflagellates_100X.jpg

http://www.infectiousdiseasenews.com/199906/S9a06587.gif

Red Tides: Another dinoflagellate

Red tides kill fish and stink!!!

Diatoms

http://www.nhm.ac.uk/hosted_sites/quekett/Others/Gallery/Helios/diatom.jpg

http://www.lifesci.ucsb.edu/mcdb/research/facilities/microscopy/diatom.jpg

http://www.acnatsci.org/research/biodiv/diatompics/diatom.jpg

This phylum of algae is noted for its symmetry and beautiful glass shells – used in toothpaste!!!

An example of diatom diversity.

More diatoms.

Red algae:

www.alumni.ca/ ~thoga3n/redalgae.gif faculty.clintoncc.suny.edu/

faculty/Michael.Gr...

* The red pigment, phycoerythrin, allows red algae to photosynthesize at greater depths

* The agar in the plates that we used for the bacteria lab was a red algae

* Carrageenan (an ingredient in many ice creams) and Nori (the wrapping around sushi) are both red algaes

Nori: red algae used for makisushi

Brown algae; you guessed it, its brown!

http://www.nmnh.si.edu/botany/projects/algae/Imag-Pha.htmhttp://www.sonoma.edu/biology/algae/Nereocystis.GIF

The largest living algae; kelp forms an underwater forest-like habitat.

Brown algae

Kelp can grow 2 feet per day!

Phylaof

Fungus-like ProtistsPlasmodium Slime Molds

Cellular Slime MoldsWater Molds & Downy

Mildews

Characteristics in Common

•All form delicate, netlike structures on the surface of their food source

•Obtain energy by decomposing organic material (externally; release enzymes to break down food and then absorb).

Fungus like protists – decompose!!

• Like dog vomit mold!!

Slime Molds

•Live in cool moist, shady places where they grow on damp, organic matter

Slime molds

• Slime molds obtain food through decomposition of organic material

• This is a slime mold> commonly found on grass. It’s called the dog vomit slime mold – eewww, gross!

Plasmodial Slime Molds•Form plasmodiumplasmodium: a mass of cytoplasm that contains many diploid nuclei but no cell walls or membranes – its feeding stageits feeding stage

•Creeps by amoeboid movement – 2.5 cm/hour

Plasmodial slime molds continued…

•May reach more than a meter in diameter

•Form reproductive structures when surroundings dry up

•SporesSpores are dispersed by the wind and grow into new plasmodium

Cellular Slime Molds•In feeding mode, they exist as individual amoebic like cells

•When food becomes scarce, they come together with thousands of their own kind to reproduce

•May look like a plasmodium

Water Molds and Downy Mildews

•Live in water or moist places•Feed on dead organisms or parasitize plants

•Fuzzy white growths•Caused the great Irish Potato Famine!!

Matching Part 1:On a separate sheet of paper, match each numbered

statement with the correct lettered organism (some used twice). Answers are on the next slide.

1. Pretty glass shells

2. Huge kelp beds

3. Lead to red tides

4. Causes African Sleeping Sickness

5. Sushi wrap

6. One type is “dog vomit”

7. Has flagella and chloroplasts

8. Have 2 flagella

9. Decompose their food

10. Causes malaria

11. Ancestors of land plants

12. Can photosynthesize at great depths

a. Dinoflagellates

b. Trypanasoma

c. Slime molds

d. Diatoms

e. Red algae

f. Brown algae

g. Green algae

h. Euglena

i. Plasmodium

Answers• 1 d• 2 f• 3 a• 4 b• 5 e• 6 c• 7 h• 8 a• 9 c• 10 I• 11 g• 12 e

Matching practice: Answers on next page

a. Dinoflagellates g. phaeophytab. Trypanasoma h. green algaec. Slime molds i. red algaed. Diatoms j. Euglenae. Paramecium k. Plasmodiumf. Giardia l. rhizopoda

1 2 3 4

5 6 7 8

Answers

• 1. i• 2. c• 3. h• 4. l• 5. e• 6. d• 7. k• 8. j

Yes, you are now excused!