Exploring Protists

Big Idea:  Microbes play a critical role in the natural world.



Kingdom Protists

There are many types of protists, but organisms in this kingdom only have a few things in common:


They are Eukaryotes.

A eukaryote is an organism that has cells that has a nucleus and membrane-bound organelles. 


They typically live in water-based environments. Most protists are unicellular (made of only one cell) and can live in colonies.  But there are some protists are are multicellular (containing more than one cell).   

Are protists prokaryotes or eukaryotes?

What is a eukaryote?

What type of environment would you typically find protists living?

Are all protists unicellular? yes or no


Obtaining Food / Nutrition / Energy

Protists have a few different methods of obtaining nutrition (food):


How do the heterotroph protists obtain their food?

How do the autotroph protists get their food?

What is an example of a protist that can do both autotrophic and heterotrophic methods of obtaining food?

What is an example of a protist that absorbs their food?

What is an example of a protist that makes their own food?

Classifying Protists

Protists are classified by how they obtain food.  Protists are organized into three main groups:


How are protists classified?


Animal - Like Protists - Protozoa

Animal - like protists are often called Protozoa.  Scientists classify them by the way they move around


What are the animal-like protists often called?

How do they obtain their food / energy?

How are they classified?


Methods of Protozoa movement:

Cilia small hair-like projections all around the organism
Flagella long, thin, whip-like structure
Pseudopodia "false feet" - temporary extensions of a cell's cytoplasm that help them move around and change their shapes to absorb their food
Parasites move along with the host they invaded


What is the method of movement that uses a long, whip-like tail?

What is the method of movement that uses "false feet"?

What are cilia?


Types of Protozoa:

Phylum Sarcodina Phylum Ciliophora Phylum Zoomastingina Phylum Sporozoa
Common Name - Sarcodines Common Name - Ciliates Common Name - Zooflagellates Common Name - Sporozoan
Move by using Pseudopodia Move by using Cilia Move by using Flagella Adults do not move
Example:  Amebas 


Example:  Paramecium

Example: Trypanosoma
(causes African Sleeping Sickness)


Example: Plasmodium
(causes Malaria)


What is an example of a protozoa that uses a flagella for movement?

What type of protist phylum uses cilia? 


Plant/Algal - Like Protists 


Plant/Algal-like protists are eukaryotes that are similar to plants.  Scientists classify these protists by the color of their pigments.


Giant kelp belongs to a diverse group of organisms called algae. Simpler than most land plants, algae have no roots, stems, leaves or flowers. They range in size from microscopic cells to 100-foot-tall giant kelp.


Green Algae Brown Algae Red Algae Diatoms Dinoflagellates Golden Algae Euglena

What are plant/algal-like protists similar to?

How are they classified?

How do they obtain food/energy?  autotroph or heterotroph?

What do they do for the environment?

Why are they not plants?

What type of plant/algal-like protist can grow up to 100 feet?


Fungal - Like Protists 


Fungal-like protists are multi-cellular eukaryotes that are absorptive heterotrophs which means they must absorb their food for nutrients, unlike animals like us in which we eat (ingest) our food.

Are fungal-like protists unicellular OR multi-cellular?

How do they obtain their food? And what is this called?

What is the job of the fungal-like protists?

Give an example of a fungal-like protist.


Protists - Review - answer on handout

Copyright 2011 - Gina Isabelli - Central High School - Champaign, IL - Sophomore Biology