1. Exploring Diversity
Protists

2. Characteristics Most diverse of all organisms
Most are unicellular, microscopic organisms
Most reproduce by asexual reproduction, some can reproduce sexually
Carry out cell division
Protists are thought to have evolved 1.5 billion years ago

3. What Unites Protists?
Kingdom contains all eukaryotes that cannot be classified as animals, plants, or fungi
Lack specialized features that characterize the other 3 multicellular kingdoms
Major phyla are very different from one another

4. Protist Video

6. Amoebas Phylum: Rhizopoda
Protists that move by using flexible, cytoplasmic extensions  pseudopodia
Reproduce asexually
Live in fresh/salt H2O

7. Algae Protists that autotrophs (uni/multicellular)
Distinguished by the type of photosynthetic pigment they contain, & their cell or body shape
3 Types:
Green Algae (mostly freshwater & unicellular)
Red Algae (most are marine & multicellular)
Brown Algae (most marine & multicellular)

8. Green Algae Most are freshwater unicellular organisms
Contain the same pigments found in the chloroplasts of plants

9. Red Algae Found in warm ocean waters
Red pigments are efficient at absorbing light that penetrates deep waters

10. Brown Algae Found mostly in marine environments
Larger brown algae  Kelp, grows along coasts – provide food & shelter for different organisms
Among the largest organisms on Earth

11. Diatoms Phylum: Bacillariophyta
Photosynthetic, unicellular protists with double shells
Found in oceans & lakes
Important producers in food chain

12. Dinoflagellates Unicellular phototrophs, most are marine
Some produce powerful toxins
Create poisonous “red tides” that occur in coastal areas
Reproduce asexually

13. Euglenoids
Freshwater protists with 2 flagella, generally (example Euglena)
1/3 contain chloroplasts & are photosynthetic. 2/3 are heterotrophic
Asexual reproduction

14. Kinetoplasts
Unicellular heterotrophs, with at least 1 flagellum, some have thousands
One type causes African sleeping sickness
Trichonympha live in gut of termites and help to digest wood

15. Ciliates Example Paramecium
Have large numbers of cilia (hairlike projections)
Complex unicellular heterotrophs
Reproduction is usually
asexual, can reproduce
sexually by conjugation

17. Parmecium Movie

18. Protistan Molds Heterotrophs with some mobility
Originally thought to be related to fungi

19. Cellular Slime Molds Resemble amoebas
During environmental stress, they gather together & move toward a fixed center

20. Plasmodial Slime Molds
Group of organisms that stream along as a plasmodium  mass of cytoplasm that looks like an oozing slime
As the move, they engulf bacteria & other organic material

21. Sporozoans
Parasitic protists that form spores during their reproductive cycle
All are parasitic & cause many serious diseases
Ex.) Cryptosporidium  found in feces of infected animals

23. Beneficial Protists
Many live in digestive tracts of humans & the digestive tracts of animals that humans eat (help cows digest cellulose)
Make up plankton in ocean (producers in food web)
Major oxygen producers
Break down dead materials (recycle)

25. Malaria One of the most deadly diseases in humans
Symptoms: severe chills, fever, sweating, confusion, & great thirst
Spread by the bite of certain mosquitoes
Treatment: quinine  chemical from the bark of the cinchona tree