Characteristics and Diversity of Protists: Exploring their Reproduction, Movement, and Impact on Health

1. Chapter 21 Protists Section 1: Characteristics of Protists Section 2: Protist Diversity Section 3: Protists and Health

2. Section 1 Characteristics of Protists Objectives: • List the characteristics of protists. • List three environments where protists can be found. • Identify the unifying features of protists. • Distinguish asexual and sexual reproduction of Chlamydomonas. • Differentiate two ways multicellular protists reproduce sexually.

3. Section 1 Characteristics of Protists Diversity • Characteristics The kingdom Protista contains the most diverse groups of eukaryotic organisms of any kingdom. Protists live in moist environments and can be either free-living or parasitic. • The First Eukaryotes Protists were the first eukaryotes to have evolved about 1.5 billion years ago. • What Unites Protists The kingdom Protista contains all eukaryotes that cannot be classified as animals, plants, or fungi.

4. Section 1 Characteristics of Protists Reproduction • Sexual Reproduction in Unicellular Protists Some unicellular protists can reproduce sexually in times of stressful environmental conditions. • Sexual Reproduction in Multicellular Protists Two ways that sexual reproduction occurs in multicellular protists are alternation of generations and conjugation.

5. Section 2 Protist Diversity Objectives: • Identify how amoebas and forams move. • Describe the structure of diatoms. • Contrast three kinds of algae. • Differentiate three different kinds of flagellates. • Summarize the general characteristics of a Paramecium.

6. Section 2 Protist Diversity Ameboid Movement • Amoebas Amoebas move using cytoplasmic extensions called pseudopodia. • Foraminifera Forams have porous shells, called tests. Long, thin projections of cytoplasm extend through the pores in the tests to aid in swimming and catching prey.

7. Section 2 Protist Diversity Algae • Characteristics Algae are strictly photosynthetic protists that can be multicellular or unicellular. Algae are classified based on the type of photosynthetic pigment they contain. • Green Algae Green algae are multicellular or unicellular and contain chlorophyll. • Red Algae Red algae are multicellular with red pigments and have a complex life cycle. • Brown Algae Brown algae are multicellular with brown pigments and contain the largest organisms on earth.

8. Section 2 Protist Diversity Diatoms • Diatoms Diatoms are unicellular protists with glasslike double shells.

9. Section 2 Protist Diversity Flagellates • Characteristics Flagellates move with the use of a flagella. • Dinoflagellates Dinoflagellates are associated with poisonous “red tides.” • Euglenoids Euglenas have chloroplasts and an eye spot.

10. Section 2 Protist Diversity Flagellates continued • Kinetoplasts Some kinetoplasts live symbiotically in the guts of termites where they provide the enzymes that digest wood. • Ciliates Ciliates are the most complex and unusual of the protists that contain cilia for mobility and feeding.

11. Section 2 Protist Diversity Protistan Molds • Characteristics Protistan molds resemble fungi, but they are considered protists. • Cellular Slime Molds Cellular slime molds normally live as individual cells and aggregate for sexual reproduction. • Plasmodial Slime Molds Plasmodial molds live as colonial organisms and form sexual reproductive structures that form and spread spores. • Other Molds Oomycetes are molds that live as saprophytes or parasites.

12. Section 2 Protist Diversity Sporozoans Characteristics All sporozoans are parasitic and have complex life cycles.

13. Section 3 Protists and Health Objectives: • Identify two ways that protists affect human health. • Name three human diseases, other than malaria, caused by protists. • Summarize how malaria is transmitted. • Evaluate the methods used to control malaria.

14. Section 3 Protists and Health Protists and Humans • Beneficial Protists Protists positively affect human health through their participation in food webs, through commensal relationships with humans and their food sources, and by recycling vital resources.

15. Section 3 Protists and Health Malaria • Disease and Protists Protists negatively affect human health by causing diseases in humans and their food sources. Protists cause diseases such as dysentery, giardiasis, toxoplasmosis, and malaria. • Malaria Life Cycle Protist,Plasmodium, has a complex life cycle that involves a mosquito, human blood, and liver cells. • Treating and Preventing Malaria Drugs and mosquito control can be used to control malaria.