Chapter 25 Protists Table of Contents Section 1 Characteristics of Protists Section 2 Animal-like Protists Section 3 Plantlike and Funguslike Protists Section 4 Protists and Humans.

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Transcript Chapter 25 Protists Table of Contents Section 1 Characteristics of Protists Section 2 Animal-like Protists Section 3 Plantlike and Funguslike Protists Section 4 Protists and Humans.

Chapter

25 Protists Table of Contents Section 1

Characteristics of Protists

Section 2

Animal-like Protists

Section 3

Plantlike and Funguslike Protists

Section 4

Protists and Humans

Chapter

25 Section 1 Characteristics of Protists Objectives

•

Define

protist.

•

Describe

a hypothesis for the origin of eukaryotic cells.

•

Explain

how protists are classified.

•

Describe

the two major ways by which protists obtain energy.

•

List

three structures protists use for movement.

•

Describe

how protists reproduce.

Chapter

25 Section 1 Characteristics of Protists A Diverse Group of Eukaryotes

•

Protists

are unicellular or simple multicellular eukaryotic organisms that are not plants, fungi, or animals.

Chapter

25 Section 1 Characteristics of Protists Characteristics of Protists Click below to watch the Visual Concept.

Visual Concept

Chapter

25 Section 1 Characteristics of Protists

A Diverse Group of Eukaryotes, continued •

The First Eukaryotes

– Evidence suggests that the first protists arose from endosymbiotic prokaryotes.

Chapter

25 Section 1 Characteristics of Protists Origin of Eukaryotic Cells Click below to watch the Visual Concept.

Visual Concept

Chapter

25 Section 1 Characteristics of Protists Classification

• Protists are classified by the characteristics that make them fungus-like, plant-like, or animal-like.

Chapter

25 Section 1 Characteristics of Protists Characteristics

•

Unicellular and Multicellular

– Most protists are unicellular, but some form large, multicellular bodies.

Chapter

25 Section 1 Characteristics of Protists Comparing Organisms that are Unicellular and Multicellular Click below to watch the Visual Concept.

Visual Concept

Chapter

25 Section 1 Characteristics of Protists Characteristics

,

continued

•

Nutrition

– Many protists are

autotrophs,

organisms that make their own food. – Other protists are

heterotrophs,

organisms that must get their food by eating other organisms or their byproducts.

Chapter

25 Section 1 Characteristics of Protists

Characteristics, continued •

Motility

– Protists use

flagella, cilia,

or

pseudopodia

locomotion.

for

Chapter

25 Section 1 Characteristics of Protists Reproduction

• Protists reproduce either asexually, sexually, or both. • They reproduce asexually by

binary fission

or

multiple fission.

• They often reproduce sexually by

conjugation.

Section 2 Animal-like Protists

Chapter

25 Objectives

•

Discuss

the key characteristics of Protozoa, Ciliophora, Sarcomastigophora, and Apicomplexa.

•

Describe

how protozoa use pseudopodia to move and to capture food.

•

Explain

how ciliates move and reproduce.

•

Describe

how mastigophorans move and capture food.

•

Describe

the role of apicomplexans in disease.

Section 2 Animal-like Protists

Chapter

25 Phylum Protozoa

• Animal-like protists can be found in the phylum Protozoa.

• Protozoa use large, rounded, cytoplasmic extensions called

pseudopodia

for both movement and feeding.

Section 2 Animal-like Protists

Chapter

25

Phylum Protozoa, continued •

Protozoan Diversity

– Protozoans include organisms that inhabit the oceans, lakes, soil and even the human intestines.

Section 2 Animal-like Protists

Chapter

25 Phylum Ciliophora

• Animal-like protists include the phylum Ciliophora. • Ciliates move using cilia, which are short, hairlike, cytoplasmic projections that line the cell membrane.

Section 2 Animal-like Protists

Chapter

25

Phylum Ciliophora, continued •

Characteristics

– Ciliates have the most elaborate organelles, including two types of nuclei.

Section 2 Animal-like Protists

Chapter

25 Feeding Habits of a Ciliate Click below to watch the Visual Concept.

Visual Concept

Section 2 Animal-like Protists

Chapter

25

Phylum Ciliophora, continued •

Reproduction

– Ciliates reproduce asexually by binary fission and sexually by conjugation.

Section 2 Animal-like Protists

Chapter

25 Phylum Sarcomastigophora

• Animal-like protists include the phyla Protozoa,

Sarcomastigophora.

• For locomotion, sarcomastigophorans use flagella.

Section 2 Animal-like Protists

Chapter

25 Phylum Apicomplexa

• Animal-like protists include the phyla

Apicomplexa.

• These protists are animal parasites.

Section 2 Animal-like Protists

Chapter

25 Types of Animal-like Protists Click below to watch the Visual Concept.

Visual Concept

Chapter

25 Section 3 Plantlike and Funguslike Protists Objectives

•

Describe

four main body forms of algae.

•

List

the common name for each of the seven phyla of plantlike protists.

•

Explain

how green algae and plants are similar.

•

Describe

four phyla of funguslike protists.

•

Compare

plasmodial slime molds, cellular slime molds, and water molds.

Chapter

25 Section 3 Plantlike and Funguslike Protists Characteristics of Algae

•

Algae

can be unicellular, colonial, filamentous, or multicellular. • Seven phyla of plantlike protists are Chlorophyta, Phaeophyta, Rhodophyta, Bacillariophyta, Dinoflagellata, Chrysophyta, and Euglenophyta.

Chapter

25 Section 3 Plantlike and Funguslike Protists Plantlike Protists

•

Phylum Chlorophyta (Green Algae)

– The phylum Chlorophyta contains more than 17,000 identified species of protists called green algae.

– Both green algae and plants have chlorophylls and

accessory pigments

, store food as starch, and have cell walls made up of cellulose.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Plantlike Protists, continued •

Phylum Phaeophyta (Brown Algae)

– The phylum Phaeophyta includes approximately 1,500 species of multicellular organisms called brown algae. – Brown algae are mostly marine organisms, and they include plantlike seaweeds and kelps.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Plantlike Protists, continued •

Phylum Rhodophyta (Red Algae)

– The 4,000 species in the phylum Rhodophyta are known as red algae. – A few species of red algae live in fresh water or on land, but most red algae are marine seaweeds.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Plantlike Protists, continued •

Phylum Bacillariophyta (Diatoms)

– The phylum Bacillariophyta contains as many as 100,000 species of unicellular protists called

diatoms.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Plantlike Protists, continued •

Phylum Dinoflagellata (Dinoflagellates)

– More than 2,000 species of organisms called dinoflagellates make up the phylum Dinoflagellata.

– Some species of dinoflagellates, such as those in genus

Noctiluca

, can produce bioluminescence, a display of sparkling light often seen in ocean water at night.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Plantlike Protists, continued •

Phylum Chrysophyta (Golden Algae)

– The phylum Chrysophyta contains about 1,000 species of golden algae. Most golden algae live in fresh water, but a few species are found in marine environments.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Plantlike Protists, continued •

Phylum Euglenophyta (Euglenoids)

– The phylum Euglenophyta contains about 1,000 species of flagellated unicellular algae called euglenoids.

– Euglenoids are both plantlike and animal-like. Many are autotrophic, like plants, but they lack a cell wall and are highly motile, like animals.

Chapter

25 Section 3 Plantlike and Funguslike Protists Structure of

Euglena

Chapter

25 Section 3 Plantlike and Funguslike Protists Funguslike Protists

• Biologists recognize two groups of funguslike protists: slime molds and water molds.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Funguslike Protists, continued •

Phylum Myxomycota (Plasmodial Slime Molds)

–

Plasmodial slime molds

are multinucleate.

– As the plasmodium creeps along the forest floor by cytoplasmic streaming, it consumes decaying leaves and other debris by phagocytosis.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Funguslike Protists, continued •

Phylum Dictyostelida (Cellular Slime Mold)

–

Cellular slime molds

live as individual haploid cells that move about like amoebas. – Each cell moves as an independent organism, creeping over the ground or swimming in fresh water and ingesting food.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Funguslike Protists, continued •

Phylum Oomycota (Water Molds)

– Water molds are composed of branching filaments and many of this phylum are parasitic.

Chapter

25 Section 3 Plantlike and Funguslike Protists

Funguslike Protists, continued •

Phylum Chytridiomycota (Water Molds)

– Members of phylum Chytridiomycota, or the

chytrids,

are primarily aquatic protists characterized by gametes and zoospores with a single, posterior flagellum.

Section 4 Protists and Humans

Chapter

25 Objectives

•

State

four environmental roles of protists.

•

Describe

algal blooms and red tides and their impact.

•

State

an important role for protists in research.

•

List

a use of protists as food and three uses of protist byproducts.

•

Describe

four protist-caused diseases.

Section 4 Protists and Humans

Chapter

25 Protists in the Environment

• Protists produce large amounts of oxygen, form the foundation of food webs, recycle materials, and play a role in several symbiotic relationships.

Section 4 Protists and Humans

Chapter

25

Protists in the Environment, continued •

Ecology of Protists

–

Algal blooms

can lead to the depletion of oxygen in water. – Red tides produce harmful toxins.

Section 4 Protists and Humans

Chapter

25 Protists in Research

• Research on protists has helped biologists understand a number of fundamental cellular functions, such as leukocyte movement.

Section 4 Protists and Humans

Chapter

25 Protists in Industry

•

Protists as Food

– For thousands of years, humans have been collecting seaweeds for food.

Section 4 Protists and Humans

Chapter

25

Protists in Industry, continued •

Protist Byproducts

– Protists provide important byproducts, such as

alginate, carrageenan,

and

agar.

Section 4 Protists and Humans

Chapter

25 Protists and Health

• Parasitic protists cause malaria, giardiasis, cryptosporidiosis, and trichomoniasis in humans.

Section 4 Protists and Humans

Chapter

25 Protists and Health

•

Malaria

– Parasitic protists in the genus

Plasmodium

cause

malaria,

which is characterized by severe chills, headache, fever, and fatigue. – Each year, nearly 3 million people die from malaria.

Chapter

25 Life Cycle of

Plasmodium

Section 4 Protists and Humans

Section 4 Protists and Humans

Chapter

25 Malaria Life Cycle Click below to watch the Visual Concept.

Visual Concept