1. Protists
Biology
Chapter 20

2. 20-1: The Kingdom Protista
Protista: Greek: “the very first”

3. What is a Protist? Most diverse kingdom Protist may be:
Unicellular or multicellular
Microscopic or very large
Autotrophic or heterotrophic
Protists are eukaryotes that are not members of the kingdom Plantae, Animalia, or Fungi
There is no “typical protist”

4. PROTISTS ENDOSYMBIONT THEORY
Early eukaryotes developed symbiotic relationships with prokaryotic cells
Prokaryotic cells lived inside eukaryotic cells
Over time, the smaller prokaryotic cells evolved with the eukaryotic cells to become mitochondria and chloroplasts

5. Evolution of First Eukaryote(s)
Forces leading to eukaryote
Increases in size
Increases in complexity
Mechanisms
Infolding of cell membrane
Serial endosymbiosis of membrane-bound organelles
Best guess for mechanism based on observations to date
Mitochondria and chloroplasts are about the size of prokaryotes
Chemistry of them is more similar to related prokaryotes than to the chemistry in rest of cytosol
Mitochondria and chloroplasts have their own genes, arranged in simple DNA loops like prokaryotes
Endosymbiosis is a common occurrence among present day forms (among all kindoms)
This took place way back in time, maybe as long ago as 1500 mya (early Proterozoic)
Of course, it happened in the early ocean.

6. Classification of Protist
3 basic types based on how they obtain their nutrients
Protozoa
Animal-like
All unicellular
Plantlike
Resemble plants because they are autotrophs
Do not have roots, stems, and leaves
Funguslike protist
Resemble fungi because they decompose dead organisms

7. PROTIST CLASSFICATION
Separated by feeding habits (nutrition)
Autotrophic
Able to make own food
Photosynthetic – 30-40% of all photosynthesis worldwide is done by algae
Heterotrophic
Must eat other material
Unicellular
May be predators, decomposers, or parasites

8. PROTISTS ANIMAL LIKE PROTISTS = PROTOZOA PLANT LIKE PROTISTS = ALGAE
Classified by method of movement
PLANT LIKE PROTISTS = ALGAE
Classified by pigment color
FUNGUS LIKE PROTISTS = MOLDS
Classified by body form

9. Watch video on Protists

10. 20-2: Animal-like Protists: Protozoans
Protozoan: “first animals”

11. What is a Protozoan? All are unicellular heterotrophs
Feed on other organisms or dead matter
Typically reproduce asexually but can reproduce sexually
Grouped by method of movement (4)
Zooflagellates: flagella
Sarcodines pseudopods
Ciliates: cilia
Sporozoans :non-motile: do not move

12. tiny beating hair-like structures
Protozoans
classified by the 4 ways they move:
1) Cilia -
tiny beating hair-like structures
Coordinated movement between individual cilia
2) Flagellum(a) -
whip-like tail(s)
Back and forth wave motion

13. classified by the 4 ways they move:
Protozoans
classified by the 4 ways they move:
3) Pseudopodia -
projection of cytoplasm that sticks out like a foot (“false foot”)
4) Sessile -
No locomotion (_________)
movement

14. Phylum Zoomastigina
Often called flagellates because they move using 1 or 2 flagella
Absorb food by diffusion through cell membrane
Live off of dead or decaying organic matter or some are parasites
Reproduce asexually by mitosis and cytokinesis
Sexually by meiosis

15. symbiotic relationship:
Trichonympha
Trichonympha lives in the gut of termites and helps termite digest cellulose in wood.
symbiotic relationship:
MUTUALISM

16. One flagellate, Trypanosoma, causes African Sleeping Sickness
1) Infected Tsetse fly bites human,
2) Trypanosoma enters blood stream, causes lethargy, swollen lymph nodes,
3) effects central nervous system and causes death if not treated.
Every day, about 100 people die from the disease.
Every day, about 100 people die from the disease.

17. Trypanosoma

18. Giardia Giardiasis: transmission by contaminated water
Causes diarrea and vomiting
ALWAYS BOIL WATER WHEN CAMPING: boiling water will kill giardia

19. PHYLUM SARCODINA Live in moist places (most live in saltwater)
irregular shape
Amoeboid movement - move by pushing out extensions of cytoplasm called pseudopodia (false foot)
Plasmolemma – elastic cell membrane
NO cell wall
Cytoplasm is divided into ectoplasm and endoplasm
Nucleus, contractile vacuole, food vacuole
During extreme conditions some form cysts
Example: Amoeba proteus

20. Amoeba proteus: quiz Endoplasm Ectoplasm
Know all structures and their functions!

21. Ameoboid movement Click on the link below to watch ameoboid movement

22. Amoeba proteus
feeding sequence
psuedopodia surround and engulf food particle
process called phagocytosis

23. Watch video of amoeba feeding

24. Foraminferans and Helizoans Shelled Sarcodines

25. Ciliates Phylum Ciliophora Live in any aquatic habitat
Use cilia for feeding and movement
Examples
Paramecium
Typically undergoes asexually but can undergo conjugation (exchange of genetic material)

26. PHYLUM CILIOPHORA
Ciliates – found in fresh and salt water; usually free-living, most are larger than other protozoa
Pellicle, cilia, ectoplasm, endoplasm, food vacuole, contractile vacuole
Micronucleus (exchanged during conjugation)
Macronucleus (controls daily functions)

27. PHYLUM CILIOPHORA
TRICHOCYSTS – spindle shaped alternating between bases of cilia; used as anchor and to paralyze prey
Oral groove – shallow furrow on one side of cell used to gather food
Locomotion – cilia; avoiding reaction  contact with unfavorable conditions and will move away
Reacts to contact, temperature, gravity, water currents, electric currents, acidity and other chemicals

28. Paramecium caudatum
Anal pore
Know each term in the diagram

29. Reproduction Example = paramecium Mitosis every 6-12 hours
Conjugation – become sticky and adhere to each other at oral groove and exchange nuclear material
Example = paramecium

30. Quiz yourself 4 3 1 5 2 6 9 7 10 8

31. Unicellular, slipper-shaped move by coordinated beating of many cilia
Paramecium movement
Unicellular, slipper-shaped
move by coordinated beating of many cilia

32. Watch a paramecium feeding

33. Paramecium: food to waste pathway

34. Undulating membrane in groove (ciliary)
Food vacuoles
Oral groove on surface
Macronucleus
w/ micronuclei behind
Cilia
Contractile vacuoles
Food particles
Site of cell “anus”

35. Paramecium reproduction
1. Binary fission (________)
asexual
N =
nucleus
F =
Fission plane

36. Paramecium reproduction
2. Conjugation (________)
sexual
Form structure called conjugation tube to exchange genetic material
Micronucleus is exchanged

37. Watch a paramecium reproducing

38. Sporozoans Most produce spores All are parasites
Found in blood or intestines
Example
Plasmodium
Genus that causes malaria in humans
Transmitted by female Anopheles mosquitoes
More than million people have malaria & million die of malaria every year

40. Chloroquine: drug used to treat malaria BUT……..

41. Toxoplasma (not in book)

42. Cryptosporidium (not in book)
Can be a problem in public splash areas