1. Kingdom Protista
Chapter 19

2. What is a protist? Protists may be: Are all eukaryotes.
unicellular or multicellular.
microscopic to very large.
heterotrophic or autotrophic.
beneficial, parasitic, or innocuous.
Are all eukaryotes.
There are 3 major categories of protists:
animal-like protists
plant-like protists
fungus-like protists

3. Protozoa: The animal-like protists
unicellular
heterotrophic
reproduction
usually asexually
sometimes sexually
4 main groups
amoebas
flagellates
ciliates
sporozoans

4. Phylum Rhizopoda: The Amoebas
Are shapeless protists
Move and feed with the aid of cytoplasm filled projections called pseudopodia (false foot)
Live in mostly marine environments, but are also found in freshwater environments

5. Phylum Zoomastigina: The Flagellates
Protozoans with one or more flagella
Some are parasites
ex. Trypanosoma brucei (African sleeping sickness)
Some are beneficial
ex. Trichonympha spp. (termites)

6. Phylum Ciliophora: The Ciliates
Are covered with cilia that aid in locomotion
Live in aquatic environments
ex. Paramecium

7. Phylum Sporozoa: The Sporozoans
Most produce spores
spore is a reproductive cell
forms without fertilization
All are internal parasites
Have complex life cycles
Ex. Plasmodium, which causes malaria

8. Algae: The plant-like protists
Are photosynthetic autotrophs
Are unicellular or multi-cellular
Unicellular (also know as phytoplankton)
euglena
diatoms
dinoflagellates
Multicellular:
red algae
brown algae
green algae

9. Phylum Euglenophyta: The Euglenoids
Are unicellular
Are both autotrophic and heterotrophic
Have a flagella
Photosynthesize when light is favorable
Ingest food when light is not favorable
Do NOT have a cell wall, but have a flexible
pellicle made of protein

10. Phylum Bacillariophyta: The Diatoms
Are unicellular
Photosynthetic autotrophs
Have shells composed of silica (SiO2)
Aquatic environments

11. Phylum Dinoflagellata: Dinoflagellates
Have cell walls composed of cellulose
Have two flagella located in grooves at right angles to each other
Mostly marine
Some live in symbiotic
relationships
ex. coral
Some are toxic
ex. Gonyaulux catanella
(red tide)

12. The Multicellular Algae: 3 Phyla
Rhodaphyta: red algae
Live in deep waters
Phaeophyta: brown algae
Include kelp
Have air bladders to float
Chlorophyta: green algae
Most diverse (>7000 spp.)
Ex. Volvox & Spirogyra

13. The Fungus-like Protists
Are all heterotrophic decomposers
Two main groups with 3 phyla
The slime molds
Myxomycota
Acrasiomycota
Water molds and downy mildews
Oomycota

14. Phylum Myxomycota Consist of the plasmodial slime molds Plasmodium:
mass of cytoplasm that contains many diploid nuclei but contain no cell walls or membranes
Move at ~2.5cm/hr
Can reach 1m+ in diameter and contain thousands of nuclei
Can reproduce asexually or sexually

15. Phylum Acrasiomycota Consist of the cellular slime molds
Spend part of their life as a single amoeboid cell
Forms a mass, like a plasmodium, when food is scarce but is multicellular with plasma membranes
Cells are haploid for their entire life cycle.

16. Phylum Oomycota Water molds Downy mildews Appear white and fuzzy
Produce flagellated reproductive cells
Downy mildews
Have caused major crop destruction
Phytophthora infestans : responsible for the Irish potato famine of the 1840’s