11.1& 11.2 Protists and Kinds of protists

Warm up How many different types of cells do you

recognize in the following figure?

Introduction

Some are tiny that they cannot be seen without a microscope. Others grow many meters long. Some are poisonous. And some provide food for people. What are they??

Objectives

Describe the characteristics of protists. Describe four ways that protists get food. Explain the meaning of heterotrophs. Define decomposers Explain how protists can be parasites.

Characteristics of protists Protist: a protist is a member of the kingdom

protista. Protists differ from other living things in many ways.

The following figure shows different types of protists:

Characteristics of protists

They are very diverse and have few traits in common. Can be single-celled, many cells or live in colonies. Some protists produce their own food, some eat other

organisms or decaying matter Some protists can control their own movement and other

can’t. All protists are eukaryotic and have nucleus. Protists are less complex than other eukaryotic organisms Unlike fungi, plants or animals, protists have no

specialized tissues

Protists and food

Protists get food in many ways. Some protists can make their own food. Other protists eat other organisms, parts or products of other organisms, or the remains of other organisms. Some protist use more than one method of getting food.

Producing food, finding food What are producers? Some protists act like green plant and produce their

own food through photosynthesis since they contain chloroplasts.

What are heterotrophs? Heterotrophs are organisms that can’t make their own

food, they rather get food from their environment. These organisms eat other organisms, parts or products

of other organisms, or the remains of other organisms

Decomposers Some protists are decomposers

since they feed on the remains of other organisms or they get energy by breaking down organic matter.

Some protists get energy in more than one way. Ex: slime molds, get energy by engulfing both small organisms and particles of organic matter.

Parasites Some protists are parasites. A parasite invades another

organism to get the nutrients that it needs and cause harm.

An organism that a parasite invades is called a host.

Parasitic protists invade fungi, plants or animals.

Kinds of protists

Objectives:1- describe how protists can be organized into three groups based on their shared traits.2- List an example for each group of protists.

Kinds of protists

One way that protists are grouped is based on shared traits.

Scientists can place protists into three groups:1- producers2- heterotrophs that can move3- heterotrophs that can’t move

Protist producer Many protists are producers like plant. How????? These protist producers are called Algae All algae have the green pigment chlorophyll, which is

used in making food. Most algae also have other pigments that give them

color. Almost all algae live in water Algae can be single-celled or many celled Some of these algae can grow to many meters in

length

Protist producer Free-floating single-celled algae are

called phytoplankton. They can’t be seen without a microscope. They usually float near the water’s

surface. They provide food for most other

organisms in the water. They also produce much of the world’s

oxygen.

Euglenoids or euglena Euglenoids are producers protists they make

their own food since they have chlorophyll. They live in fresh water. They do have flagella which helps them

moving

Heterotrophic protists

Heterotrophic protists cannot make their own food. They are consumers, decomposers, or parasites. Those that can move are sometimes called protozoans. Like Amoeba.

Amoeba Amoebas are soft, jelly like protozoans. They are found in both fresh and salt water, in

soil and as parasites in animals. They are mobile heterotrophs since they have

pseudopods.

Wrap up

What are protists? What are the three types of protists? What are phytoplanktons? What are protozoans?