By: Christian, Tony, and Sean

Introduction

• Simple Eukaryotic organisms• Study started in 1675• Most are unicellular• Most live in oceans or fresh water• Many different kinds, with many different traits• Many serve as a major food source for other organisms

Structure of Protists• Eukaryotic• Uni-cellular (Multi-cellular in some stages)• Some have Flagella (Comes out of reservoir)• Some have Cilia• Membrane bound organelles• Nucleus• Eyespot• Some have chloroplasts for photosynthesis• Cell membrane• Some have a cell wall• Food vacuole• Endoplasm• Cytoplasm• Oral groove• Anal pore

Feeding• Some are autotrophic• Some are heterotrophic• Structures for making and eating food

This amoeba is busy capturing a ciliate by surrounding it with its pseudopodia. The nucleus can be seen just below the pseudopodia. Bottom left is a water expelling vesicle.Vorticella attaches itself to plants

and algae and sweeps food into its mouth-like opening at the top of the bell with hair-like structures called cilia (shown in yellow). It eats bacteria and small protozoans.

This suctorian ciliate is feeding on protozoan.

Reproduction

Mitosis• Parent cell divides

• Turns into two cells

• Each resulting cell is ½ size of parent cell

• Occurs in protists such as Amoebas

Meiosis• Occurs in protists such as Paramecia

•Two cells join at oral grooves

• Genetic material is transferred

• Several divisions occur, resulting in eight new cells

Euglenophyta (Euglenoids)

Chrysophyta (Golden Algae)

Pyrrophyta (Fire Algae)

Myxomycota (Slime Molds)

Sarcodina (Sacrcodines)

Cilliata (Cilliates)

Sporozoa (Sporozans)

Mastigophora (Flagellates)

Euglenas

Diatoms

Dino Flagellates

Slime Molds

Amoebas

Paramecia

Plasmodium

Trypanosomes

SPECIES

Major Phyl a and

Red algae (Rhodophyda) Trichonypha

Trypanosoma

Euglena Viridis

Plasmodium in RBC (malaria)

Dinoflagellate

Tetrahymena

Entamoeba Hystolictica (causes Dysentery)

Amoeba

Images

More Images

Summary• Eukaryotic and unicellular• Complex• Different types• Reproduce by both meiosis and mitosis• Are both asexual and sexual• Some are heterotrophic• Some are autotrophic• Move with flagella or ciliae• Some are parasites

Unidentified ciliate protists attacking a juvenile Lampsilis.  One of the uni-cells (arrow) is forcing its way between the partly open valves of the mussel.  These protists can also invade the marsupia and feed on glochidia.  However, it is not yet clear whether they attack healthy juveniles or merely act as scavengers on dead or dying individuals.  

Additional Notes

•Autotrophic protists contain chloroplasts and carry out photosynthesis.

•Protists are grouped as Algal-like, Fungal-like, or Animal-like (protozoans)