1. Kingdom Protista- Chapter 20 Biology 111

2. Protists  Protists are single celled eukaryotes. A few forms are multi-cellular.  Heterotrophic or autotrophic  Most live in water  Protist is any organism that is not a plant, animal or fungus

3. Classification of Protists 1. How they obtain nutrition 2. How they move

4. Classification cont… Protists are classified into 3 main groups: 1. Animallike Protists - also called protozoa (means "first animal") - heterotrophs 2. Plantlike Protists - also called algae - autotrophs 3. Funguslike Protists - heterotrophs, decomposers, external digestion 1. Animallike Protists - also called protozoa (means "first animal") - heterotrophs 2. Plantlike Protists - also called algae - autotrophs 3. Funguslike Protists - heterotrophs, decomposers, external digestion

5. Animal-like Protists Four Phyla of Animallike Protists Classified by how they move A. Zooflagellates - flagella B. Sarcodines - extensions of cytoplasm (pseudopodia) C. Ciliates - cilia D. Sporozoans - do not move

6. A. Zooflagellates  Flagellates have a small number of long flagella, long whiplike hairs that beats to propel the cell.  Some nasty parasites are flagellates, including Giardia lamblia, which causes diarrhea and which is found in most of the surface waters of the US.  Another is Trypanosoma brucei, which causes sleeping sickness in Africa. Also Trichmonas vaginalis, a sexually transmitted disease.

7. B. Sarcodines  moves using pseudopodia ( "false feet" ), which are like extensions of the cytoplasm --ameboid movement  ingests food by surrounding and engulfing food (endocytosis), creating a food vacuole  reproducing by binary fission (mitosis)  contractile vacuole - removes excess water  can cause amebic dysentery in humans - diarrhea and stomach upset from drinking contaminated water

8. Amoebas in Action

9. C. Ciliates  Cilia are small hairs surrounding the protist’s body. The cilia beat in a synchronized pattern to cause movement.  Paramecium is a typical ciliate. It has a gullet to swallow food, and a contractile vacuole to get rid of excess water.  Genetics: the DNA used for sexual reproduction is stored in the small micronucleus. A copy of this information is used to run the cell: the copy is kept in the much larger macronucleus. http://biologycorner.com/bio1/paramecium_movement.html

10. D. Sporozoans  Sporozoans are animal-like protists that have part of their life cycle inside the cells of their hosts.  The most important example is Plasmodium, the parasite that causes malaria. Malaria kills 1-2 million people each year.  Mosquitoes are part of the life cycle. They suck blood from infected humans, ingesting the sporozoans. The sporozoans undergo sexual reproduction in the mosquito’s gut.  When the mosquito bites another person, the sporozoans infect the blood and liver of the host. The parasites multiply asexually inside the red blood cells, destroying them as they leave.

11. Vector / Protist?

12. Plant-like Protists: Algae  The plant-like protists are called algae. Most are single-celled, but a few form large multicellular seaweed.  The plant-like protists have chloroplasts. Some, like the Euglena, also have flagella for movement.  Some, such as the diatoms, have calcium carbonate (chalk) or silica shells.

13. Multicellular Algae  The multicellular algae are commonly called seaweed. They can be classified into red, brown, and green algae. All have chloroplasts, but the pigments in the chloroplasts vary, giving the different colors.  Some, like kelp, are very large and contain several different types of cells and tissues to do specialized work. These include leaves for photosynthesis, gas- filled bladders for buoyancy, the root-like holdfast, and tubes to transport nutrients throughout the body.  Algae contain the polysaccharide “agar”, which is tasteless and is used to thicken foods such as soft ice cream, and used in petri dishes as food for microbes.

14. Algae Blooms  Algae blooms are the sudden growth of a large population of single celled algae. They occur near the coastlines, with the algae feed on fertilizer runoff and sewage. Algae blooms deplete the oxygen in the water, killing fish and other organisms.  Some of the algae also secrete toxins. Ex: Red tide

15. Green Algae  The green algae are the ancestors of plants. The term “plant” implies living on the land or derived from plants living on the land. Green algae and plants have very similar chloroplasts.  Multicellular green algae ex: volvox

16. Fungus-like Protists: water & slime molds  Like fungi, they are heterotrophs: they get food and energy from other organisms (live or dead).

17. More Fungus-like Protists  The water molds include some of the worst plant diseases.  Phytphthora infestans causes rot in plants. In the 1840’s, Phytophthora caused the potato blight in Ireland. The Irish were poor and overcrowded, and lived mostly on potatoes. The blight caused crop failures in several years, resulting in the deaths of of the population. Many Irish came to the US/Canada at that time.