1. Unit 2 - Kingdom Protista

2. KEY CONCEPTS
Protists are a diverse group of eukaryotic organisms, most of which are microscopic

3. What Are Protists? “Dumping ground” kingdom Eukaryotic
Heterotrophic and/or autotrophic
Single or multicellular
Ancestors to animals, plants, fungi

4. All Life Functions in Just One Cell
Have food and waste VACUOLES for storing and digesting food & wastes
Many are capable of MOVEMENT
RESPOND to environment – some have light sensitive eyespot
Amoeba
Paramecium

5. All Life Functions in Just One Cell
Maintain HOMEOSTASIS
Contractile Vacuoles pump out excess water
Form Protective Cysts when food or water is scarce (dormant stage with hard covering)
Contractile Vacuole Pumping

6. Reproduction Reproduction Asexual: fission
Binary Fission - divides into 2 identical individuals (clones)
Rapid reproductive rate

7. Some Reproduce SEXUALLY
Sexual: produce gametes (specialized sex cells)
Advantage: new combinations of genes from both parents

8. Protist Characteristics
Eukaryotic
Unicellular
Some may live in colonies
May be Autotrophic or Heterotrophic or Both
Some are motile
Appeared about 1.5 BYA

9. Classified into Three Main Groups
Animal-like… heterotrophs capable of locomotion
Plant-like… photosynthetic autotrophs
Fungus-like… decomposers that reproduce by spores
Some protists may exhibit both animal-like & plant-like characteristics

10. Classification of Selected Medically Important Protozoa
Four groups
Mastigophora - flagellates
Sarcodina - amoebae
Ciliophora - ciliates
Apicomplexa – aka Sporozoans
Based on:
Method of motility
Mode of reproduction
Stages in the lifecycle

11. Animal-like Protists classified by method of movement

12. Phylum Rhizopoda: ex. Amoeba

13. The Amoeba uses pseudopodia for locomotion.

14. Amoeba surround and engulf their food… the process is called phagocytosis. An Amoeba eating a Paramecium.

15. Amoeba

16. Phylum Ciliophora all use cilia for movement
have many specialized structures, including mouths, anal pores, contractile vacuoles, and two nuclei (a large macronucleus and small micronuclei)
Ex. – Paramecium and Stentor

17. Phylum Ciliophora: ex. Paramecium

18. Ciliates

19. Phylum Sporozoa are parasites have no means of locomotion
form spores that are dispersed by one or more hosts
ex. Plasmodium, which causes malaria

20. Portions of the Life Cycle of Plasmodium vivax
It’s Vector: Anopheles Mosquito
Red Blood Cells

21. Malaria

22. Giardiasis Fecal-oral route of infection
recreational water, water, fomites, contaminated uncooked food
Symptoms normally begin 1 to 2 weeks (average 7 days) after becoming infected.
Symptoms
Diarrhea
Stomach or abdominal cramps
Upset stomach or nausea
May lead to weight loss and dehydration
Symptoms of giardiasis may last 2 to 6 weeks.

23. Plant-like Protists are classified by COLOR

24. Plant Like Protista Few cause disease Many are microscopic
Importance of Protists
Autotrophic protists = algae
Photosynthetic algae are the most important primary producers of the world’s freshwater and marine ecosystems
Many are microscopic
Some are huge: kelp
Few cause disease
Toxic blooms of dinoflagellates cause
Red tides
shellfish poisoning

25. Diatoms
Giant Kelp

26. Photosynthetic Producers
Energy
Photosynthesis
6 CO2 + 6H2O C6H12O6
Respiration
Energy

27. Phylum Euglenophyta
have one to three flagella at their leading (apical) end
have an eyespot that permits them to swim toward light
can become heterotrophic when there is no light

28. Euglena (arrow indicates anterior end)
The Euglena uses a flagella as a means of locomotion.

29. Evolutionary Considerations
One group of flagellates, the choanoflagellates, is thought to have given rise to the simplest animals, the sponges.