Section 1 Characteristics of Protistss3.amazonaws.com/scschoolfiles/136/mb_25_win.pdf · • Phylum...

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Resources Chapter menu

Protists Chapter 25

Table of Contents

Section 1 Characteristics of Protists

Section 2 Animal-like Protists

Section 3 Plantlike and Funguslike Protists

Section 4 Protists and Humans



Section 1 Characteristics

of Protists Chapter 25

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

A Diverse Group of Eukaryotes

• Protists are unicellular or simple multicellular

eukaryotic organisms that are not plants, fungi, or

animals.


of Protists



Chapter 25

Characteristics of Protists


of Protists



Chapter 25

A Diverse Group of Eukaryotes, continued

• The First Eukaryotes

– Evidence suggests that the first protists arose from

endosymbiotic prokaryotes.


of Protists



Chapter 25

Origin of Eukaryotic Cells


of Protists



Chapter 25

Classification

• Protists are classified by the characteristics that

make them fungus-like, plant-like, or animal-like.


of Protists



Chapter 25

Characteristics

• Unicellular and Multicellular

– Most protists are unicellular, but some form large,

multicellular bodies.


of Protists



Chapter 25

Comparing Organisms that are Unicellular

and Multicellular


of Protists



Chapter 25

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.


of Protists



Chapter 25

Characteristics, continued

• Motility

– Protists use flagella, cilia, or pseudopodia for

locomotion.


of Protists



Chapter 25

Reproduction

• Protists reproduce either asexually, sexually, or both.

• They reproduce asexually by binary fission or

multiple fission.

• They often reproduce sexually by conjugation.


of Protists



Chapter 25

Protist Reproduction


of 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.




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.




Chapter 25

Phylum Protozoa, continued

• Protozoan Diversity

– Protozoans include organisms that inhabit the

oceans, lakes, soil and even the human intestines.




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.



Chapter 25

Paramecium





Chapter 25

Phylum Ciliophora, continued

• Characteristics

– Ciliates have the most elaborate organelles,

including two types of nuclei.



Chapter 25

Feeding Habits of a Ciliate





Chapter 25

Phylum Ciliophora, continued

• Reproduction

– Ciliates reproduce asexually by binary fission and

sexually by conjugation.




Chapter 25

Phylum Sarcomastigophora

• Animal-like protists include the phyla Protozoa,

Sarcomastigophora.

• For locomotion, sarcomastigophorans use flagella.




Chapter 25

Phylum Apicomplexa

• Animal-like protists include the phyla Apicomplexa.

• These protists are animal parasites.



Chapter 25

Types of Animal-like Protists




Section 3 Plantlike and Funguslike

Protists Chapter 25

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.




Protists Chapter 25

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.




Protists Chapter 25

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.




Protists Chapter 25

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.




Protists Chapter 25


• 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.




Protists Chapter 25


• Phylum Bacillariophyta (Diatoms)

– The phylum Bacillariophyta contains as many as

100,000 species of unicellular protists called

diatoms.




Protists Chapter 25


• 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.




Protists Chapter 25


• 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.




Protists Chapter 25


• 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




Protists Chapter 25

Funguslike Protists

• Biologists recognize two groups of funguslike protists:

slime molds and water molds.




Protists Chapter 25

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.




Protists Chapter 25


• 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.




Protists Chapter 25


• Phylum Oomycota (Water Molds)

– Water molds are composed of branching filaments

and many of this phylum are parasitic.




Protists Chapter 25


• 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.




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.




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.




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.




Chapter 25

Protists in Research

• Research on protists has helped biologists

understand a number of fundamental cellular

functions, such as leukocyte movement.




Chapter 25

Protists in Industry

• Protists as Food

– For thousands of years, humans have been

collecting seaweeds for food.




Chapter 25

Protists in Industry, continued

• Protist Byproducts

– Protists provide important byproducts, such as

alginate, carrageenan, and agar.




Chapter 25

Protists and Health

• Parasitic protists cause malaria, giardiasis,

cryptosporidiosis, and trichomoniasis in 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




Chapter 25

Malaria Life Cycle




Multiple Choice

1. Most scientists believe that protists evolved from

which of the following?

A. fungi

B. plants

C. euglenoids

D. prokaryotes

Standardized Test Prep Chapter 25



Multiple Choice, continued

1. Most scientists believe that protists evolved from

which of the following?

A. fungi

B. plants

C. euglenoids

D. prokaryotes





2. Protist habitats are often characterized by the

presence of which of the following?

F. soil

G. algae

H. blood

J. moisture





3. Flagella are characteristic of members of which

phylum?

A. Protozoa

B. Ciliophora

C. Apicomplexa

D. Sarcomastigophora





Use the table below to answer questions 4 - 5. The table shows cases of amebiasis and malaria in the United States between 1986 and 1994.





4. How many people had malaria in 1992?

F. 1,087

G. 1,229

H. 1,292

J. 2,942





5. How did the number of cases of amebiasis change between 1986 and 1994?

A. The number of cases increased.

B. The number of cases decreased.

C. The number of cases stayed the same.

D. The number of cases increased, then decreased.





Complete the following analogy:

6. Bacillariophyta : autotrophs :: Apicomplexa :

F. cilia

G. flagella

H. parasites

J. plasmodium





Use the graph below to answer

question 7. The graph shows the

cycle of fever in a malaria patient.


7. In this patient, how

often does the

cycle of fever

repeat?

A. every 12 h

B. every 24 h

C. every 48 h

D. every 96 h



Short Response

Anopheles mosquitoes require water to breed.

What would happen to malaria cases during a dry

season and during a wet season?




Short Response, continued

Anopheles mosquitoes require water to breed.

What would happen to malaria cases during a dry

season and during a wet season?

Answer: During the dry season, malaria cases

would decrease because there are fewer

mosquitoes. Cases would increase during the

wet season because there are more mosquitoes.





Extended Response

Base your answers to parts A & B on the information below.

A scientist wants to examine the effect of fertilizer on algal blooms. In the laboratory, the scientist adds increasing amounts of fertilizer to three samples of pond water and adds no fertilizer to a fourth sample of pond water.

Part A Which samples will show increased algal growth? Explain your answer.

Part B How can the scientist apply his or her laboratory results to a natural ecosystem? Compare the scientist’s experiment to a natural ecosystem, such as a pond.




Extended Response, continued

Answer:

Part A All of the samples to which fertilizer was added

should show increased algal growth in proportion to the

amount of fertilizer added. The nutrients in fertilizer

promote algal growth.

Part B Sample answer: The scientist can study water

samples from the environment for the amount of

fertilizer in each. He or she can then compare the water

samples to his laboratory results. The scientist’s

experiment lacks some of the factors found in

ecosystems, such as algal consumers, changes in

weather, and additional nutrients.

Section 1 Characteristics of Protistss3.amazonaws.com/scschoolfiles/136/mb_25_win.pdf · • Phylum...

Documents

Transcript of Section 1 Characteristics of Protistss3.amazonaws.com/scschoolfiles/136/mb_25_win.pdf · • Phylum...