This document outlines Chapter 20 on protists. It discusses the three main groups of protists - animal-like protists (protozoa), plant-like protists (algae), and fungus-like protists. For animal-like protists, it describes different phyla including zooflagellates, sarcodines, ciliates and sporozoans. It also discusses how some protists can cause diseases like malaria. For plant-like protists, it outlines different types of algae and their pigments. Plant-like protists are important as the base of aquatic food chains. Fungus-like protists obtain nutrients externally and include water molds and slime molds, serving important ecological

1. Ch. 20 Protists

2. Ch. 20 Outline
 20-1: The Kingdom Protista
 What is a Protist
 Classification of Protists
 20-2: Animal-like Protists: Protozoans
 Zooflagellates
 Sarcodines
 Ciliates
 Animal-like Protists and Disease
 Ecology of Animal-like Protists

3. Ch. 20 Outline
 20-3: Plant-like Protists: Unicellular Algae
 Chlorophyll and Accessory Pigments
 Euglenophytes
 Chrysophytes
 Diatoms
 Dinoflagellates
 Ecology of Unicellular Algae

4. Ch. 20 Outline
 20-4: Plant-like Protists: Multicellular Algae
 Red Algae
 Brown Algae
 Green Algae
 Human Uses of Algae
 20-5: Fungus-like Protists
 Ecology of Fungus-like protists

5. What is a Protist?
 Protist: Any eukaryotic organism that is not
a plant, animal, or fungus.
 Kingdom Protista is the most diverse
kingdom. They can be unicellular or
multicellular

6. Classification of Protists
 One way to classify protists is by how they
obtain nutrition:
 Heterotrophs – animal like
 Autotrophs – plant like
 Decomposers/Parasites – fungus like

7. Phyla Tree

8. Zooflagellates
 Animal-like protists that swim using a flagella
are classified in the Phylum zoomastigma
and are often referred to as zooflagellates.
 Flagella: Long, whiplike projection that enable
movement.

9. Sarcodines
 Sarcodines are animal-like protists that use
pseudopods for feeding and movement
 Ex. Amoebas
 Amoebas capture food by surrounding it, then
taking it in and forming a food vacuole.
 Food Vacuole: small cavity in the cytoplasm
that temporarily stores food.

10. Amoeba
Pseudopods

11. Ciliates
 Members of the phylum Ciliophora, known as
ciliates, use cilia for feeding and movement.
 Cilia beat like oars
 Ex. Paramecium
 Anatomy of a Paramecium
 Macronucleus: “Working Library” of a genetic
information
 Micronucleus: contains a “reserve copy” of all the cell’s
genes
 Gullet: Indentation on one side of the organisms (food
enters here)
 Anal Pore: Region where waste is emptied
 Contractile vacuole: Expels excess water

12. Paramecium

13. Sporozoans
 Members of the Phylum Sporozoa do not
move one their own and are parasitic.

14. Animal-like Protists and
Disease
 Protists can causes some diseases.
 Example: Malaria
 Caused by the sporozoans Plasmodium, which
is carried by the Anopheles mosquito
 Plasmodium infects liver cells and RBC’s where
it reproduces causing those cells to burst

15. Malaria

16. Ecology of Animal-like
Protists
 Recycle nutrients in the environment
 Serve as food for larger animals
 Live symbiotically with other organisms
 Ex. Trichonympha live in the guts of termites
and enable them to digest wood (by the enzyme
cellulase)

17. Chlorophyll and Accessory
Pigments
 Many protists contain the green pigment,
chlorophyll and carry out photosynthesis.
One the ways plant-like protists are
categorized is by the type of photosynthetic
pigment they contain.
 Accessory pigments: absorb light at
different wavelengths than chlorophyll
 Review: The energy from sunlight is used by
photoautotrophs to make sugars for food

18. Euglenophytes
 These protists have two flagella but no cell
wall.
 Ex. Euglena
 Eyespot: Reddish pigment near the gullet
 Senses light
 Euglena can also be heterotrophic

19. Euglena
Gullet
Chloroplast
NucleusEyespotFlagella
Carbohydrate
storage bodies
Pellicle
Contractile
vacuole

20. Chrysophytes
 These protists have gold-colored
chloroplasts
 Ex. Yellow-green and golden-brown algae

21. Diatoms
 Diatoms produce thin, delicate cell walls rich
in Silicon (Si) – the main component in
glass.
 Used in pesticides – Like Shrapnel!

22. Dinoflagellates
 Many of these are lumniscent.
 About half are photosynthetic and half are
heterotrophs.
 They have two flagella also.

23. Dinoflagellates

24. Ecology of Unicellular Algae
 Plant-like protists serve as the base of a
food chain in many aquatic ecosystems
 Phytoplankton: population of small,
photosynthetic organisms found nears the
surface of the ocean.
 Protists make up much of phytoplankton

25. Agal Blooms
 When waste is high the number of plant-like
protists increases greatly (since they use the
organic matter for food). This is called a
bloom
 A “red tide” is a bloom of dinoflagellates.
They give off a toxin that harms both
humans and fish.

26. Red Algae
 Red Algae are able to live at great depths
due to their efficiency in harvesting light
energy. Red Algae contain chlorophyll a
and reddish accessory pigments called
phycobilins.

27. Brown Algae
 Brown Algae contains chlorophyll a and c,
as well as a brown accessory pigment called
fucoxanthin.

28. Green Algae
 Green Algae share many characteristics with
plants, including their photosynthetic
pigments and cell wall composition.
 Pigments: a and b

29. Human Uses of Algae
 Photosynthesis  oxygen in atmosphere
 Chemicals in algae used in medicines
 Food source
 Chemicals used to make plastics, waxes,
paints and more!

30. Fungus-like Protists
 Like fungi, funguslife protists obtain their
food by digesting outside their bodies
(heterotrophs), but they do not have cell
walls of chitin like fungi.
 Two types of mold:
 Slime Molds
 Water Molds

31. Water Mold

32. Slime Mold
MEIOSIS
FERTILIZATION
ZygoteGerminating
spore
Spores
Young
sporangium Mature
plasmodium
Feeding
plasmodium
Haploid (N) Diploid (2N)
Mature
sporangium

33. Ecology of Fungus-like
Protists
 Important recyclers of organic material
 Decomposers of dead things!
 Some cause plant diseases
 Potato Blight in Ireland caused by water mold
 Lead to Irish immigration to America