1. Chapter 11
Section 2 Kinds of Protists
Bellringer
Do you know what algae is? Have you ever seen it? What does it look like? Algae needs a lot of water in order to live. Where do you suppose most algae live?

2. Chapter 11
Section 2 Kinds of Protists
Objectives
Describe how protists can be organized into three groups based on their shared traits.
List an example for each group of protists.

3. Chapter 11 Protist Producers
Section 2 Kinds of Protists
Protist Producers
Scientist place protists into three groups based on their shared traits: producers, heterotrophs that can move, and heterotrophs that can’t move.
Many protists are producers. Like plants, protist producers use the sun’s energy to make food through photosynthesis. These protist producers are know as algae.

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Some algae are made of many cells and generally live in shallow water along the shore. You may know these algae as seaweeds.
Phytoplankton are the microscopic algae that float near the surface of marine or fresh water.

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Red Algae Most of the world’s seaweeds are red algae and live in tropical oceans, attached to rocks or to other algae.
Green Algae The green algae are the most diverse group of protist producers. Most live in water or moist soil. But others live in melting snow, on tree trunks, and inside other organisms.

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Brown Algae Most of the seaweeds found in cool climates are brown algae. They attach to rocks or form large floating beds in ocean waters.
Diatoms are single celled. They are found in both salt water and fresh water and make up a large percentage of phytoplankton.

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Dinoflagellates have two whiplike strands called flagella. The beating of these flagella causes the cells to spin through the water. Most dinoflagellates live in salt water, but some live in fresh water or snow.
Euglenoids are single-celled protists and live in fresh water. Many euglenoids are producers, but can also get food as heterotrophs. Other eugelnoids are full time consumers or decomposers.

8. Heterotrophs That Can Move
Chapter 11
Section 2 Kinds of Protists
Heterotrophs That Can Move
Heterotrophic protists that can move are often called protozoans.
Amoebas and similar amoeba-like protists are soft, jellylike protozoans. They are found in both fresh and salt water, in soil, and as parasites in animals.
Although amoebas look shapeless, they are highly structured cells.

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Amoebic Movement Amoebas and amoeba-like protists move with pseudopodia. Pseudopodia means “false feet.” Amoebas and amoeba-like protists use pseudopodia to catch food, too.
Shelled Amoeba-Like Protists Not all amoeba-like protists look shapeless. Some have an outer shell.

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Zooflagellates Flagellates are protists that wave flagella back and forth to move. Some flagellates live in water. Others live in the bodies of other organisms.

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Ciliates Ciliates are complex protists. They have hundreds of tiny, hairlike structures known as cilia. Ciliates use their cilia for movement and also for feeding. The best-known genus of ciliates is Paramecium.

12. Chapter 11
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13. Heterotrophs That Can’t Move
Chapter 11
Section 2 Kinds of Protists
Heterotrophs That Can’t Move
Some protist heterotrophs are parasites that do not move about. Others can only move at certain phases of their life cycle.
Spore-Forming Protists Most spore-forming protists are parasites. They absorb nutrients from their hosts. Spore-forming protists have complicated life cycles that usually include two or more hosts.

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Water Molds live in water, moist soil, or other organisms. Some of them are decomposers and thus eat dead matter. But many are parasites.
Slime Molds can move only at certain phases of their life cycle. Live in cool, moist places in the woods. They use pseudipodia to move around. But when environmental conditions are stressful, they form spores that cannot move.