Chapter 11

Protists

Chapter 11: Section 1 Objectives

Describe the characteristics of protists.

Describe 4 ways that protists get food.

Describe 3 ways protists reproduce.

Protists

What are protists?– Members of Kingdom Protista– They come in a range of sizes– Some are poisonous– Very diverse group

– Protista is a very diverse group with few traits in common.

– What does diverse mean?

General Characteristics

Very diverse. Have few traits in common. Can be uni-cellular, multi-cellular, or live in

colonies. Can be producers, consumers, or

decomposers. All are eukaryotic.

– What does this mean about their cells?

General Characteristics

Related more by how they differ than by how they are similar.

Less complex than other eukaryotic organisms. (do not have specialized tissue).

Fungi, plants, and animals have specialized tissues that have specific functions.

Protists and Food

Protists get food in many ways:

– Some eat organisms (consumers)

– Some make their own food (producers) These protists contain chlorophyll and get their food through

photosynthesis.

– Others eat dead or decaying organisms (decomposers)

Producers

Produce their own food through photosynthesis.

Have specialized structures called chloroplasts in their cells.

Chloroplasts capture energy from the sun. Plants use this same process to produce

food.

Finding Food

Some protists must get their food from the environment.

Heterotrophs are organisms that cannot make their own food.

These organisms get food through 1 of the following methods:

– Eat other organisms– Eat parts/products of other organisms– Eat remains of organisms

Finding Food

Many protist heterotrophs eat small living organisms, such as bacteria, yeast, or other protists.

Some protists can get food in more than one way.

For example, some species of slime molds are decomposers and consumers.

Finding Food

Some protist heterotrophs are parasites. A parasite invades another organism to get

the nutrients that it needs. An organism that a parasite invades is called

a host. Do parasites cause harm to, benefit, or

cause no harm to their host?

Producing Protists

Kingdom Protista is a very diverse group. Like all living things, protists reproduce. Most protists reproduce asexually. These offspring are identical to the parent.

– Traits are pulled from only one parent. Like bacteria, they reproduce by binary

fission. Some reproduce by sexual reproduction.

Section 2: Objectives

Describe how protists can be organized in 3 groups based on shared traits.

List an example of each of the protist groups.

Kinds of Protists

Protists are hard to classify because of so much diversity in the group.

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

Scientists are constantly discovering new traits/characteristics about protists so they are hard to classify.

Kinds of Protists

Protists are placed into 3 groups:– Producers– Heterotrophs that can move– Heterotrophs that can’t move

These groups do not show how protists are related to each other except for 2 traits.

Protist Producers

Protist producers use the sun’s energy to make food through photosynthesis.

These protists are known as algae. All algae have the green pigment chlorophyll. Most algae have other pigments that give

them color. Almost all algae live in water.

Protist Producers

Multi-cellular algae live in shallow water along the shore.

Free-floating uni-cellular algae are called phytoplankton.

These algae cannot be seen without a microscope. These algae usually float near the water’s surface. These produce much of the world’s oxygen.

– Why would these algae need to live in shallow water?

Red Algae

Most of the world’s seaweed is red algae. Most live in tropical oceans attached to

rocks. These contain chlorophyll, but a red pigment

gives them their color. This red pigment allows them to absorb light

that filters into deep water.

Green Algae

This is the most diverse group of protist producers.

Chlorophyll is the main pigment in their cells. Most live in water or most soil. Can be uni or multi-cellular. Individual cells of some species live in small

groups called colonies.

Ch. 1 Sec. 1-2 Pop Quiz

1) List 3 general characteristics of protists. 2) _______ capture energy from the sun. 3) What are heterotrophs? 4) Some heterotrophs are ________. 5) Most protist reproduce ________. 6) List the 3 groups that protists are placed in 7) Free-floating uni-cellular algae are called

____________. 8) _______ is the most diverse group of protists.

Brown Algae

Found in cool climates. Attach to rocks or form large floating masses. Contain chlorophyll and a yellow pigment. Form very large masses that can grow up to

60 meters. Produce food through photosynthesis.

Diatoms

Single-celled. Found in both salty and fresh water. Get their energy through photosynthesis. Make up a large percentage of

phytoplankton. Cell walls of diatoms contain a glasslike

substance called silica.

Dinoflagellates

Single-celled. Most live in salty water. Have 2 whip-like strands called flagella. Use these strands for movement. Most are producers. Some are consumers and decomposers.

Euglenoids

Single-celled protists. Most live in fresh water. Use their flagella to move through the water. Most are producers. When there is not enough light to make food,

they can be heterotrophs.

Heterotrophs That Can Move

Some heterotrophs have special traits that allow them to move.

Others cannot move on their own. Those that can move are usually consumers

or parasites. These mobile protists are called protozoans.

Amoebas

Found in both fresh and salt water. Look shapeless but are actually highly

structured cells. Eat bacteria and small protists. Others are parasites that depend on host

organisms. Have pseudopodia (false feet) that help them

move around.

Heterotrophs That Can’t Move

Not all protist heterotrophs have features that help them move.

Some can move only for a short period in their life.

Many are parasites and absorb nutrients from their host.

Section 3: Objectives

Describe characteristics of fungi.

Distinguish between 4 main groups of fungi.

Explain how lichens affect the environment.

Characteristics of Fungi

Eukaryotic heterotrophs Rigid cell walls No chlorophyll They are so different from other organisms

that they are placed in their own kingdom. Come in a variety of shapes, sizes, and

colors.

Food for Fungi

They are heterotrophs but cannot catch or surround food.

Must live on or near their food supply. Most fungi are decomposers. Other fungi are parasites. Some fungi live in mutualism with another

organism.– What is mutualism?

Microscopic Traits

Multi-cellular fungi are made up of chains of cells called hyphae.

The opening between cells allow cytoplasm to move freely between cells.

Most of the hyphae that make up fungus grow together to form a twisted mass called mycelium.

Making More Fungi

Can be sexual or asexual. Spores are reproductive cells that are

protected by a thick cell wall. Spore = reproductive cell of fungi Spores are light and easily spread by the

wind. When growing conditions are favorable, fungi

will grow where the spores land.

Kinds of Fungi

Thread-like fungi Club fungi Non-mushroom fungi Imperfect fungi

Thread-like Fungi

A mold is a shapeless fuzzy fungi.

Mold belongs to threadlike fungi.

These fungi reproduce asexually.

Club Fungi

These are umbrella shaped mushrooms.

These fungi reproduce sexually (spores).

These fungi have “gills” under the umbrella that allow spores to be dispersed.

Non-mushroom Fungi

Mushrooms are not the only club fungi.

Bracket fungi grow outward from trees and form small shelves or brackets.

They attack crops such as corn and wheat.

Imperfect Fungi

Includes all species of fungi that do not fit into other groups.

Most are parasites that cause diseases to plants and animals.

Some forms are useful:– Penicillium: source of the antibiotic penicillin

Lichens

A lichen is a combination of a fungus and algae that grow together.

The algae live in protective walls of the fungus.

These can grow on rocks because they need only light, minerals, and air to grow.

Ch. 11 Sec. 3 Pop Quiz

1) List 3 characteristics of fungi. 2) How do fungi get food? 3) List and describe 4 different groups of

fungi. 4) What is a spore? 5) Where do algae live in lichens?