Chapter Introduction

Lesson 1 What are Protists?

Lesson 2 What are Fungi?

Chapter Wrap-Up

What are protists and fungi, and how do they affect an environment?

What do you think?

Before you begin, decide if you agree or disagree with each of these statements. As you view this presentation, see if you change your mind about any of the statements.

1. Protists are grouped together because they all look similar.

2. Some protists cause harm to other organisms.

3. Many protists make their own food.

Do you agree or disagree?

4. Mushrooms and yeasts are two types of fungi.

5. Fungi are always helpful to plants.

6. Some fungi can be made into foods or medicines.

Do you agree or disagree?

• What are the different types of protists and how do they compare?

• How are protists beneficial?

What are Protists?

• protist

• algae

• diatom

• protozoan

What are Protists?

• cilia

• paramecium

• amoeba

• pseudopod

• A protist is a member of a group of eukaryotic organisms which have a membrane-bound nucleus.

• Protists share characteristics with plants, animals, and fungi but are not classified as any of these groups.

What are Protists?

What are Protists? (cont.)

• Most protists reproduce asexually, though some reproduce sexually.

• Scientists classify protists as plantlike, animal-like, or funguslike based on which group they most resemble.

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What are Protists? (cont.)

What are the different types of protists?

Plantlike Protists

A type of microscopic plantlike protist with a hard outer wall is a diatom.

diatom

from Greek diatomos, means “cut in two”

Plantlike Protists (cont.)

• Dinoflagellates are unicellular plantlike protists that use flagella to move.

• A euglenoid is a unicellular plantlike protist with rigid cell coat called a pellicle and a flagellum at one end of its body.

• Algae are a photosynthetic plantlike protist that can be either multicellular or unicellular.

Algae provide food for animals and animal-like protists and provide shelter for many aquatic organisms.

The Importance of Algae

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• Algae can help remove pollution from the water.

• Pollution can be a food source for algae, allowing the population of algae to increase quickly.

The Importance of Algae (cont.)

How are algae beneficial to an ecosystem?

The Importance of Algae (cont.)

• Protozoans are protists that resemble tiny animals.

• Protozoans do not have chloroplasts or make their own food.

• Protozoans are unicellular and mostly live in wet environments.

Animal-like Protists

• Cilia are short, hairlike structures that grow on the surface of some protists.

• Protists with cilia are called ciliates.

• Cilia cover the surface of the cell and move a protist through water.

• Ciliates reproduce asexually, but they can exchange some genetic material through a process called conjugation.

Animal-like Protists (cont.)

Animal-like Protists (cont.)

• A paramecium is a protist with cilia and two types of nuclei.

• A paramecium gets its food by forcing water into a groove in its side.

• A flagellate is a type of protozoan with one or more flagella.

• Flagellates eat decaying matter.

• Sarcodines are animal-like protists with no specific shape.

• An amoeba is one common sarcodine with an unusual adaptation for movement and getting nutrients.

Animal-like Protists (cont.)

• An amoeba moves and obtains nutrients by using a temporary “foot,” called a pseudopod, which forms as the organism pushes part of its body outward.

• Many protozoans are beneficial to an environment because they break down dead plant and animal matter.

Animal-like Protists (cont.)

Some protozoans can cause disease, like malaria, by acting as parasites.

The Importance of Protozoans

In what ways are protists helpful and harmful to humans?

• Funguslike protists share many characteristics with fungi.

• Slime molds are funguslike protists composed of cell material and nuclei floating in a slimy mass.

• Most slime molds absorb nutrients from other organic matter in their environment.

Funguslike Protists

Funguslike Protists (cont.)

• A water mold is a funguslike protist that lives as a parasite or feeds on dead organisms.

• Slime molds and water molds usually reproduce sexually when environmental conditions are harsh or unfavorable.

• Funguslike protists play a valuable role in the ecosystem by breaking down dead plant and animal matter, making nutrients available for living organisms.

• Many funguslike protists attack and consume living plants.

Importance of Funguslike Protists

Importance of Funguslike Protists (cont.)

How are funguslike protists beneficial to an environment?

• Protists are a diverse group of organisms that cannot be classified as plants, animals, or fungi.

• Protists are grouped according to the type of organisms they most resemble. Diatoms are one type of plantlike protist.

• Some protists use hairlike structures called cilia to move.

A. ciliate

B. protozoan

C. flagellate

D. paramecium

What is a type of protozoan with one or more flagella called?

A. sarcodine

B. pseudopod

C. flagellate

D. protozoan

An amoeba is a common form of which type of protist?

A. paramecium

B. protozoan

C. sarcodine

D. pseudopod

What is a protist with cilia and two types of nuclei called?

1. Protists are grouped together because they all look similar.

2. Some protists cause harm to other organisms.

3. Many protists make their own food.

Do you agree or disagree?

• What are the different types of fungi and how do they compare?

• Why are fungi important?

• What are lichens?

What are Fungi?

• hyphae

• mycelium

• basidium

• ascus

What are Fungi?

• zygosporangia

• mycorrhizae

• lichen

• Fungi are eukaryotes that form long, threadlike structures called hyphae which absorb minerals and water.

• Fungi are heterotrophs, meaning they cannot make their own food.

What are Fungi?

Hyphae create a network of large tangles called the mycelium.

• Scientists group fungi based on how they look and how they reproduce.

• Almost all fungi reproduce asexually by producing spores which are small reproductive cells with a strong, protective outer covering.

• Scientist recognize four groups of fungi: club fungi, sac fungi, zygote fungi, and imperfect fungi.

Types of Fungi

Types of Fungi (cont.)

What are the four groups of fungi?

Mushrooms belong to the group called club fungi.

Types of Fungi (cont.)

mushroom

Science Use a type of club fungi

Common Use the part of a fungus above the ground

Types of Fungi (cont.)

• The part of the mushroom that grows above ground is a structure called a basidiocarp.

• The basidia are the reproductive structures inside the basidiocarp that produce sexual spores.

• Many sac fungi cause diseases in plants and animals while others are harvested by people for food.

• The ascus is the reproductive structure where spores develop on sac fungi.

• Many yeasts are sac fungi, including the common yeast used to make bread.

Types of Fungi (cont.)

• Zygote fungus can cause bread to develop mold.

• The hyphae of a zygote fungus grow over materials, such as bread, dissolving the material and absorbing nutrients.

• Tiny stalks called zygosporangia form when the fungus undergoes sexual reproduction and release spores called zygospores.

Types of Fungi (cont.)

Some fungi can be used to make food, but other fungi can eat the food too.

Hutchings Photography/Digital Light Source

Hutchings Photography/Digital Light Source

Hutchings Photography/Digital Light Source

Imperfect fungi are named because scientists have not observed a sexual, or “perfect,” reproductive stage in their life cycle.

Types of Fungi (cont.)

• Many fungi and plants grow together, helping each other.

• Products such as bread, cheese, and medicines are made using fungi.

• The roots of the plants and the hyphae of the fungi weave together to form a structure called mycorrhiza.

• As fungi break down decaying matter in the soil, they make nutrients available to the plant and increase water absorption.

• Fungi use plant sugars to continue to grow.

The Importance of Fungi (cont.)

The Importance of Fungi (cont.)

• Scientists use some fungi to make important medicines like penicillin.

• As new species of fungi are discovered and studied, scientists might find new sources of antibiotics and medicines.

Describe two ways that fungi are important to humans.

The Importance of Fungi (cont.)

What are Lichens? (cont.)

• A lichen is a structure formed when fungi and certain other photosynthetic organisms grow together.

• Usually, a lichen consists of a sac fungus or club fungus that lives in a partnership with either a green alga or a photosynthetic bacterium.

What are Lichens?

lichen

from Greek leichen, means “what eats around itself”

What are Lichens? (cont.)

• Green algae and photosynthetic bacteria are autotrophs, which means they can make their own food using photosynthesis.

• The fungus provides water and minerals, while the bacterium or alga provides sugars and oxygen from photosynthesis.

Plants and animals benefit from lichens because the fungi help break down rocks and create soil where plants can grow, creating a food source for other organisms.

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What are Lichens? (cont.)

Which two organisms make up a lichen?

• The body of a fungus is made up of threadlike hyphae that weave together to create a network of mycelium.

• Club fungi produce sexual spores in the basidium.

• A lichen is made of fungus and photosynthetic bacterium or alga.

Photodisc Collection/Getty Images

A. sac

B. zygote

C. club

D. imperfect

Mushrooms are an example of what type of fungi?

A. spores

B. ascus

C. zygosporangia

D. flagellates

What is the term for the tiny stalks formed form when fungus undergoes sexual reproduction?

A. ascus

B. basidia

C. zygosporangia

D. mycorrhiza

What reproductive structures produce the sexual spores of club fungi?

4. Mushrooms and yeasts are two types of fungi.

5. Fungi are always helpful to plants.

6. Some fungi can be made into foods or medicines.

Do you agree or disagree?

Key Concept Summary

Interactive Concept Map

Chapter Review

Standardized Test Practice

Protists and fungi are diverse groups of organisms. Both may infect the human body. They are classified as neither plant nor animal and serve many functions in the ecosystem.

• Scientists divide protists into three groups based on the type of organisms they most resemble. There are plantlike, animal-like, and funguslike protists.

• Protists are beneficial to humans in many ways. They are used to create many of the useful products you depend on. They also help decompose dead organisms and return nutrients to the environment.

Lesson 1: What are Protists?

Lesson 2: What are Fungi?

• Scientists divide fungi into four groups, based on the type of structures they use for sexual reproduction. The four groups are club fungi, sac fungi, zygote fungi, and imperfect fungi.

• Fungi provide many foods and medicines that people use. In addition, fungi help break down dead organisms and recycle the nutrients into the environment.

Photodisc Collection/Getty Images

A. pellicle

B. dinoflagellate

C. euglenoid

D. cilia

Which is a unicellular plantlike protist with a flagellum at one end of its body?

A. nuclei

B. cilia

C. amoebas

D. pseudopods

What are the short, hairlike structures that grow on the surface of some protists?

A. mushrooms

B. basidia

C. hyphae

D. ascus

What are the structures on fungi which absorb minerals and water?

A. sac

B. club

C. ascus

D. zygosporangia

Which type of fungus causes bread to mold?

A. mycorrhiza

B. basidia

C. lichen

D. mycelium

Which of these structures forms when fungi and certain other photosynthetic organisms grow together?

A. ascus C. diatom

B. fungus D. protist

Which of these is a eukaryotic organism and has a membrane-bound nucleus?

A. euglenoid

B. flagella

C. spore

D. diatom

Which of these enables a dinoflagellate’s movement?

A. microscopic plants

B. tiny animals

C. algae

D. euglenoids

Protozoans are described as resembling which of these?

A. mycorrhizae

B. bacteria

C. zygosporangia

D. spores

The roots of plants and the hyphae of fungi weave together to form which of these?

A. flagellate

B. club

C. basidia

D. ascus

What is the name for the reproductive structure of sac fungi?