Chapter 19: Protists

Chapter 19 Organizer Protists

Refer to pages 4T-5T of the Teacher Guide for an explanation of the National Science Education Standards correlations. Teacher Classroom Resources Activities/FeaturesObjectivesSection MastersSection TransparenciesReproducible

Reinforcement and Study Guide, p. 83 L2 Section Focus Transparency 45 L1 ELL Section 19.1 1. Identify the characteristics of Kingdom MiniLab 19-1: Observing Ciliate Motion, Section 19.1 Protista. p. 522 Critical Thinking/Problem Solving, p. 19 L3 Basic Concepts Transparency 30 L2 ELL The World of Protists 2. Compare and contrast the four groups Inside Story: A Paramecium, p. 523 The World of BioLab and MiniLab Worksheets, p. 89 L2 Reteaching Skills Transparency 29 L1 ELL National Science Education of protozoans. Problem-Solving Lab 19-1, p. 524 Protists Laboratory Manual, pp. 133-136 L2 Reteaching Skills Transparency 30 L1P ELL Standards UCP.1, UCP.2, Content Mastery, pp. 93-94, 96 L1 P UCP.5; A.1, A.2; C.1, C.4, P C.5, C.6; F.1, F.4, F.5 (1 ses- P Reinforcement and Study Guide, pp. 84-85P L2 Section Focus Transparency 46 L1 ELLP sion, 1 block) Section 19.2 LS BioLab and MiniLab Worksheets, p. 90 L2 Basic Concepts Transparency 28 L2P ELL P LS Algae: Plantlike Laboratory Manual, pp. 137-140 L2 P Basic Concepts Transparency 30 L2 ELLLS Section 19.2 3. Compare and contrast the variety of MiniLab 19-2: Going on an Algae Hunt, Protists Tech Prep Applications, pp. 27-28 PL2 LS P LS P LS plantlike protists. p. 527 Content Mastery, pp. 93, 95-96 L1 P 4. Explain the process of alternation of Problem-Solving Lab 19-2, p. 530 LS P Algae: Plantlike Protists LS P National Science Education generations in algae. Design Your Own BioLab: How do P LS Reinforcement and Study Guide, p. 86 L2 P Section Focus Transparency 47 L1 ELL Standards UCP.1, UCP.2, Paramecium and Euglena respond to light? Section 19.3 LS LS Concept Mapping, p. 19 L3 ELL P Basic Concepts Transparency 29 L2PLS ELL UCP.5; A.1, A.2; C.1, C.4, p. 538 P LS C.5, C.6; F.1, F.4, F.5 (2 ses- Slime Molds, BioLab and MiniLab Worksheets, pp.P 91-92 L2 Basic Concepts Transparency 30 L2PLS LSELL sions, 1 block) Water Molds, and Content Mastery, pp. 93, 95-96 LSL1P P Downy Mildews LS P LS LS P LS P Section 19.3 5. Contrast the cellular differences and life Problem-Solving Lab 19-3, p. 534 P PLS LS cycles of the two types of slime molds. Social Studies Connection: The Irish Potato Assessment Resources LS AdditionalP Resources LS P Slime Molds, Water 6. Discuss the economic importance of the Famine, p. 540 Chapter Assessment, pp. 109-114 LS Spanish Resources ELL P LS Molds, and Downy downy mildews and water molds. P P MindJogger Videoquizzes English/Spanish Audiocassettes ELL LS Mildews LS LS Performance Assessment in the Biology Classroom Cooperative Learning in the Science Classroom National Science Education LS COOP LEARN Standards UCP.1, UCP.2, Alternate Assessment in the Science Classroom P Lesson Plans/Block SchedulingP LSLS UCP.4, UCP.5; A.1, A.2; C.1, Computer Test Bank LS P LS C.3-5, C.6; F.1, F.4, F.5; G.1-3 BDOL Interactive CD-ROM, Chapter 19 quiz (2 sessions, 1/ block) 2 LS LS LS LS

Need Materials? Contact Carolina Biological Supply Company at 1-800-334-5551 KeyKey toto TeachingTeaching StrategiesStrategies or at http://www.carolina.com Teacher’s L1 Level 1 activities should be appropriate Corner MATERIALS LIST for students with learning difficulties. The following multimedia resources are available from Glencoe. L2 Level 2 activities should be within the Products Available From Index to National BioLab p. 527 microscope, microscope slide, ability range of all students. Biology: The Dynamics of Life Glencoe Geographic Magazine p. 538 microscope, microscope slides, coverslip, dropper, pond water, paper, CD-ROM ELL L3 Level 3 activities are designed for above- To order the following products, The following articles may be coverslips, dropper, metric ruler, index pencil average students. Exploration: The World of Protists call Glencoe at 1-800-334-7344: used for research relating to this cards, scissors, toothpicks, methyl cellu- BioQuest: Biodiversity Park Alternative Lab ELL ELL activities should be within the ability CD-ROM chapter: lose solution, Euglena culture, range of English Language Learners. Video: Protists p. 534 microscope, sterile agar plate, NGS PictureShow: The Cell “Slime Mold: The Fungus That P Paramecium culture COOP LEARN Cooperative Learning activities Video: Kelp Forests oat cereal flakes, plasmodium stage of P Walks,” by Lee Douglas, July P P are designed for small group work. Video: Slime Mold MiniLabs Physarum polycephalum P Products Available From 1981. P These strategies represent student prod- National Geographic Society Videodisc Program p. 522 Paramecium culture, wheat ucts that can be placed into a best-work To order the following products, ProtistsLS seeds, microscope, microscope slide, P portfolio. call National Geographic Society Kelp Forests LS coverslip, dropper LS These strategies are useful in a block LS at 1-800-368-2728: Slime Mold LS scheduling format. LS Video LS Protists: Threshold of Life 518A 518B ChapterChapter 1919 ChapterChapter SECTION PREVIEW Section Objectives Section 19.1 Identify the character- istics of Kingdom 19.1 The World of Protists Protista. ETTING TARTED EMO Protists GETTING STARTED DEMO 19 Compare and contrast Prepare Magnification: 770 the four groups of Naturalist Have students protozoans. Key Concepts observe slides containing Magnification: 300 Vocabulary a variety of living amoebas, What You’ll Learn n just a few drops of pond water, protozoan This section first presents the you can find an amazing collection algae ciliates, and flagellates. Ask You will differentiate among general characteristics of protists. of protists. Some protists will be pseudopodia the major groups of protists. I asexual reproduction Then, it discusses protozoans and them to compare and contrast You will recognize the ecolo- moving, perhaps searching for food. the organisms. Students should flagellate details the characteristics of a gical niches of protists. Others will be using photosynthesis to ciliate observe that the organisms are representative organism from P You will identify some human make food. Still others will be decom- sporozoan unicellular and move differ- diseases and the protists re- spore each of the four protozoan phyla. posing organic matter in the pond ently. sponsible for them. water. In this section, you will read Planning Why It’s Important about the great diversity of protists, LS Because protists are responsible and why, in spite of this diversity, Gather cotton and toothbrush Theme Development for much of the oxygen in the biologists group them together in bristles for MiniLab 19-1. atmosphere, and are the base Kingdom Protista. The theme of unity within for most food chains in aquatic diversity is evident throughout environments, most other or- the chapter in discussions of the ganisms depend on protists to 1 Focus characteristics of protists. The exist. theme of homeostasis is promi- A Stylonchia searching for food Bellringer GETTING STARTED nent in discussions of how the G S Before presenting the lesson, different protists carry out their Observing Protists display Section Focus Trans- life functions. View a slide of protists to ob- parency 45 on the overhead pro- serve their variety. How are the jector and have students answer protists similar? How do they What Is a Protist? protists are called protozoa (proht differ? uh ZOH uh) (singular, protozoan). the accompanying questions. Kingdom Protista contains the Unlike animals, though, all proto- L1 ELL If time does not permit teach- To find out most diverse organisms of all the zoans are unicellular. Other protists ing the entire chapter, use the more about kingdoms. Protists may be unicellular are plantlike autotrophs, using pho- the protists, visit the Glencoe BioDigest at the end of the Science Web Site. or multicellular, microscopic or very tosynthesis to make their food. ORD TransparencyP 45 Protists SECTION FOCUS large, and heterotrophic or auto- Plantlike protists are called algae (AL W Origin Use with Chapter 19, unit as an overview. www.glencoe.com/sec/science Section 19.1 trophic. In fact, there is no such jee) (singular, alga). Unlike plants, protozoa organism as a typical protist. When algae do not have organs such as From the Greek you look at different protists, you roots, stems, and leaves. Still other words protos, mean- may wonder how they could be protists are more like fungi because ing “first,” and zoa, LS Internet Address Book Magnification: meaning “animals.” 475 grouped together. The characteristic they decompose dead organisms. Protozoa are ani- P Note that all protists share is that, unlike However, unlike fungi, funguslike mal-like protists. This Amoeba is surrounding its food. The Didinium is feeding on a Paramecium. Internet bacteria, they are all eukaryotes, protists are able to move at some addresses that you find useful which means that most of their meta- point in their life and do not have in the space below for quick bolic processes occur inside their chitin in their cell walls. LS Desmids are plantlike pro- membrane-bound organelles. It might surprise you to learn how reference. tists that produce much of Although there are no typical pro- much protists affect other organisms. the oxygen you breathe. The This Euglena moves by whipping its flagellum. Beating cilia draw food into the mouth Spirostomum ambiguum tists, some resemble animals in their Some protists cause diseases, such as of this Stentor.

(inset) is an animal-like protist. method of nutrition. The animal-like malaria and sleeping sickness, that Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1 What life characteristic is each of these organisms exhibiting? 2 How are these organisms alike and different?

518 PROTISTS 19.1 THE WORLD OF PROTISTS 519 BIOLOGY: The Dynamics of Life SECTION FOCUS TRANSPARENCIES

Assessment Planner Look for the following logos for strategies that emphasize different learning modalities. Assessment Planner Multiple Kinesthetic Meeting Individual Linguistic Biology Journal, Portfolio Assessment Alternative Lab, TWE, pp. 534-535 ResourceResource Needs, pp. 520, 522, 528, 531; pp. 524, 536; Portfolio, p. 529; Portfolio, TWE, pp. 520, 529 Assessment, TWE, p. 535 ManagerManager Learning Project, p. 527; Activity, p. 528 Meeting Individual Needs, p. 533 Assessment, TWE, pp. 521, 531 BioLab, SE, pp. 538-539 Visual-Spatial Activity, p. 520; Logical-Mathematical Activity, MiniLab, TWE, p. 522 Knowledge Assessment Section Focus Transparency 45 Styles Quick Demo, pp. 521, 536; Pro- p. 525 Problem-Solving Lab, TWE, p. 530 Assessment, TWE, pp. 525, 532, 537 and Master L1 ELL ject, p. 521; Check for Understanding, Naturalist Getting Started BioLab, TWE, pp. 538-539 Alternative Lab, TWE, pp. 534-535 p. 524; Tech Prep, p. 523; Reinforce- Demo, p. 518; Biology Journal, Performance Assessment Section Assessment, SE, pp. 525, 532, 537 MiniLab, SE, pp. 522, 527 Chapter Assessment, SE, pp. 541-543 ment, p. 528; Extension, p. 536 p. 526; Check for Understanding, P Intrapersonal Portfolio, p. 520 p. 536; Reteach, p. 536 Problem-Solving Lab, TWE, pp. 524, 534 Skill Assessment 518 MiniLab, TWE, p. 527 Assessment, TWE, p. 528 519

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LS result in millions of human deaths Diversity of Protozoans Figure 19.2 Pseudopodia Quick Demo 2 Teach throughout the world every year. An amoeba feeds Many protozoans are grouped Unicellular algae produce much of on small organisms Visual-Spatial Have stu- according to the way they move. such as bacteria. Nucleus Cytoplasm Activity the oxygen in Earth’s atmosphere and Some protozoans use cilia or flagella dents observe prepared Visual-Spatial After students are the basis of aquatic food chains. to move. Others move and feed by slides of amoebas, foraminif- have read about the charac- WORD Origin Slime molds and water molds decom- sending out cytoplasm-containing erans, and radiolarians and pseudopodia pose a significant amount of organic teristics of protists, have them extensions of their plasma mem- draw a labeled diagram of each From the Greek material, making the nutrients avail- Contractile diagram a generalized protist cell. branes. These extensions are called organism they see, indicating words pseudo, mean- able to living organisms. Protozoans, vacuole They should draw their diagrams pseudopodia (sewd uh POHD ee uh). the magnification at which they ing “false,” and algae, and funguslike protists play Food vacuole to scale and label the cell podos, meaning Other protozoans are grouped view each organism. Then ask important roles on Earth. Look at organelles. Then have students “foot.” An amoeba together because they are parasites. them to describe the function uses psuedopodia Figure 19.1 to see some protists. draw and label a bacterial cell for There are four main groups of proto- A As an amoeba approaches B The food becomes C Digestive enzymes break of each labeled structure. L2 to obtain food. A B C comparison. Although this activ- zoans: the amoebas (uh MEE buz), the food, pseudopodia form enclosed in a food down the food, and the ELL ity will be difficult, it should initi- What Is a Protozoan? flagellates, the ciliates, and the sporo- and eventually surround vacuole. nutrients diffuse into the Magnification: 315 the food. cytoplasm. ate a useful discussion about the zoans (spor uh ZOH unz). P If you sat by a pond, you might characteristics of protists. L3 notice clumps of dead leaves at the Amoebas: Shapeless protists P ELL Although most amoebas live in abundant on the sea floor, have hard water’s edge. Under a microscope, a The phylum Rhizopoda includes saltwater, there are freshwater ones shells made of calcium carbonate. Assessment piece of those wet decaying leaves hundreds of species of amoebas and that live in the ooze of ponds, in wet Fossil forms of these protists help Portfolio Ask students to Tying to Previous P LS reveals a small world, probably inhab- amoebalike organisms. Amoebas have patches of moss, and even in moist geologists determine the ages of make a table that summarizes the KnowledgeP ited by animal-like protists. Although no cell wall and form pseudopodia soil. Because amoebas live in moist some rocks and sediments. Unlike differencesLS between amoebas, Ask students to compare andP a diverse group, all protozoans are to move and feed. As a pseudopod places, nutrients dissolved in the foraminiferans, radiolarians have foraminiferans, and radiolarians. contrast the terms in the word unicellular heterotrophs that feed on forms, the shape of the cell changes water around them can diffuse shells made of silica. Under a micro- L2 P pairs that follow: eukaryotes and other organisms or dead organic mat- and the amoeba moves. Amoebas form directly through their cell mem- scope, you can see the complexity of LS pseudopodia around their food, as you prokaryotes,LS heterotrophs and ter. They usually reproduce asexually, branes. However, because freshwater these shells. In addition, radiolarians LS Figure 19.1 and some also reproduce sexually. can see in Figure 19.2. amoebas live in hypotonic environ- are an important part of marine autotrophs, and motile and non- Members of Kingdom ments, they constantly take in water. plankton—an assortment of micro- motile. Eukaryotes have membrane- Protista are animal- LS bound organelles; the prokaryotes like, plantlike, and Their contractile vacuoles collect and scopic organisms that float in the funguslike. pump out excess water. ocean’s photic zone and form the lack membrane-bound organelles. C During part of their life cycle, CD-ROM C Two groupings of mostly marine base of marine food chains. Heterotrophs take in food from the funguslike protists resemble P amoebas, the foraminiferan and radi- Most amoebas commonly repro- Biology: The Dynamics environment; autotrophs produce A Animal-like protists are some types of fungi. of Life unicellular heterotrophs olarian shown in Figure 19.3, have duce by asexual reproduction, in their own food. A motile organism that move in a variety shells. Foraminiferans, which are which a single parent produces one or Exploration: The World of can move; a nonmotile organism of ways. Protists, Disc 3 cannot move. L2 ELL LS Figure 19.3 BioQuest: Biodiversity Park Foraminiferans (a) a b Disc 3, 4 and radiolarians (b) Video: Protists, Disc 3 are amoebas that P extend pseudopodia through tiny holes in their shells. Pseudo- VIDEODISC podia act like sticky STV:P The Cell B Plantlike protists nets that trap food. AmoebaLS Changing are photosynthetic Shape autotrophs and may be unicellular or multicellular !7QÖ8$"LS like this one. Magnification: 475 Amoeba With Pseudopodia Magnification: 90 Magnification: 900 !7QÖV'" 520 PROTISTS 19.1 THE WORLD OF PROTISTS 521

EETING NDIVIDUAL EEDS Portfolio MEETING INDIVIDUAL NEEDS Portfolio PROJECT Visually Impaired A Moving Analogy Comparing the Speeds of Protists the observer describes it. Instruct students to Kinesthetic Ask students to build Intrapersonal Have the students Visual-Spatial Pair up students. Have divide the number of seconds the protist tactile models to demonstrate the describe or draw some everyday one student in each pair observe a slide takes to travel across the field of view by the difference between cilia and flagella. Vel- items that are analogous in structure, containing a variety of living protists under field of view size (usually 1.5 mm). The result cro can model cilia, and pieces of string appearance, or function to protozoan the low-power magnification. While the ob- is speed in millimeters per second. Have stu- P P server watches a protozoan move across the dents repeat the process for each different taped to a ball can simulate flagella. L1 structures, such as cilia, flagella, and P ELL pseudopodia. L1 P diameter of the field of view, the partner protist they see and make a table of their should use a stopwatch to time the event as results. L2 COOP LEARN 520 521 LS LS P P LS LS

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LS LS LS MiniLab 19-1 Flagellates: Protozoans P NSIDE NSIDE with flagella NSIDE NSIDE MiniLab 19-1 Observing and Inferring II Magnification: 100 II Purpose The phylum Zoomastigina consists STORY STORY Students will discover how Para- Observing Ciliate Motion The of protists called flagellates, which P mecium respondsLS when it contacts cilia on the surface of a parame- have one or more flagella. Flagellated a solid object. cium move so that the cell nor- protists move by whipping their fla- A Paramecium Purpose mally swims through the water gella from side to side. Process Skills Students learn about the role of with one end directed forward. Some flagellates are parasites that aramecia are unicellular organisms, but their cells Paramecium’s organelles. But when this end bumps into an LS observe and infer, draw a conclu- cause diseases in animals, such as Pare quite complex. Within a paramecium are many sion obstacle, the paramecium responds by changing direction. African sleeping sickness in humans. organelles and structures that are each adapted to carry Teaching Strategies Other flagellates are helpful. For out a distinct function. Teaching Strategies Procedure Ask students to explain the Observing Paramecium example, termites like those you see Using methyl cellulose to slow ! Observe a Paramecium culture that action of the contractile vacuoles. in Figure 19.4 survive on a diet of Critical Thinking How might the contractile vacuoles of the protists interferes with Para- has had boiled, crushed wheat seeds in it for several days. wood. Without the help of a certain a paramecium respond if the organism were placed in a Paramecium caudatum mecium’s normal response. @ Carefully place a drop of water containing wheat seed Visual Learning species of flagellate that lives in the dilute salt solution? Toothbrush bristles or small particles on a microscope slide. Gently add a coverslip. Have students describe the guts of termites, some termites could pieces of cotton may be used to # Using low power, locate a paramecium near some wheat location, shape, and function not survive on such a diet. In a mutu- seed particles. CAUTION: Use caution when working with of each organelle. L1 block the path of Paramecium. a microscope, glass slides, and coverslips. alistic relationship, flagellates convert 1 Cilia The cell is encased by an Have students make a table Remind students to use cau- $ Watch the paramecium as it swims around among the cellulose from wood into a carbohy- outer covering called a pellicle tion when working with micro- particles. Record your observations of the organism’s through which thousands of with the headings Function drate that both they and their termite 6 Anal pore Waste responses each time it contacts a particle. tiny, hairlike cilia emerge. The 6 scopes, slides, and coverslips. hosts can use. materials leave the and Organelle. Beneath the paramecium can move by Function head, have students Have students wash their Analysis beating its cilia. cell through the hands after handling cultures. 1. Describe what a paramecium does when it encounters an Ciliates: Protozoans with cilia anal pore. list: Digestion, Locomotion, obstacle. Protection, Excretion, Hom- Expected Results The roughly 8000 members of the 2. How long does the paramecium’s response last? eostasis, and Reproduction. protist phylum Ciliophora, known as Paramecium typically reverses the 3. Describe any changes in the shape of the paramecium as it ciliates, use the cilia that cover their 2 Oral groove Paramecia Instruct the students to use the direction in which its cilia are moved among the particles. feed primarily on bacteria P bodies to move. Use the MiniLab on diagram to complete their beating and backs away from a that are swept into the tables. L2 solid object that it contacts. this page to observe a typical ciliate’s gullet by cilia that line motion. Ciliates live in every kind of the oral groove. Critical Thinking Analysis more identical offspring by dividing aquatic habitat—from ponds and 1. It backs up, then proceeds into two cells. When environmental streams to oceans and sulfur springs. 5 Contractile vacuole Because Because less water wouldLS move forward in a new direction. conditions become unfavorable, some What does a typical ciliate look like? a paramecium lives in a fresh- into the cell if it were in a dilute types of amoebas form cysts that can To find out, look at the Inside Story 3 Gullet Food moves into the water, hypotonic environment, salt solution, the contractile vac- 2. briefly water constantly enters its cell gullet, becoming enclosed at Pore 3. The cell turned on its long survive extreme conditions. on the next page. by osmosis. A pair of contrac- uoles would collect less water and the end in a food vacuole. contract lessP frequently. axis, and it folded. Enzymes break down the tile vacuoles pump out the food, and the nutrients excess water. b diffuse into the cytoplasm. Pore opens and Full Assessment vacuole contracts vacuole Figure 19.4 a LS Portfolio Have students The flagellated pro- draw what occurs when Para- tozoans (a) that live VIDEODISC mecium encounters solid objects in the guts of ter- 4 Micronucleus and STV: The Cell and write captions for the events. mites (b) produce macronucleus The small micronucleus plays Cilia on Paramecium, Use the Performance Task enzymes that digest wood, making nu- a major role in sexual Canals take SEM Image Assessment List for Scientific trients available to reproduction. The large up water from Drawing in PASC, p. 55. L2 their hosts. macronucleus controls cytoplasm !7QÜ$#" P the everyday functions of the cell. Canals Empty vacuole Macro- and Micronucleus Identified ResourceResource 522 PROTISTS Magnification: 100 523 LS ManagerManager 19.1 THE WORLD OF PROTISTS !7QÜ.$" BioLab and MiniLab P MEETING INDIVIDUAL NEEDS Worksheets, p. 89 L2 Reteaching Skills Trans- Gifted handle glass microscope slides and coverslips parency 29 and Master Kinesthetic Ask students to place a carefully and to use special care when view- Charting Protist Diseases L1 ELL LS disease, giardiasis, and amoebic dysentery. termite on a glass slide, grasp its head ing slides under high power. Then, ask stu- Visual-Spatial Have students use an Ask them to use the column headings: with a forceps, and gently pull to separate dents to observe the slide under low- and encyclopedia to make a table about the Kingdom, Phylum, Means of locomotion, P the head and intestines from the body. Have high-power magnification, looking for the causal agents and symptoms of the following Method of transmission, Parasitic or free-liv- students add a few drops of Ringer’s solu- termite’s intestinal flagellates. Ask them to P diseases: malaria, sleeping sickness, Chagas ing, and Disease symptoms. L2 P tion or water to the termite intestines, add diagram and label the flagellates they see P a coverslip, and press gently on the coverslip and place their drawings in their portfolios. 522 to squash the intestines. Remind them to L3 ELL LS 523 LS LS P LS P P P LS LS LS LS Reteach Many structures found in ciliates’ Problem-Solving Lab 19-1 Until World War II, the drug qui- few serious side effects in humans. cells may work together to perform Have students list five general P Problem-Solving Lab 19-1 Drawing a Conclusion nine was used to treat malaria. Today, a But, some species of Plasmodium have just one important life function. For protist traits and then make a combination of the drugs chloroquine begun to resist these drugs. There- Purpose example, Paramecium uses its cilia, second list of protozoan-specific How do digestive and primaquine are most often used fore, quinine is once again being used Analyze the role of digestive oral groove, gullet, and food vacuoles traits. L1 enzymes function to treat this disease because they cause to treat the resistant strains. enzymes inLS Paramecium. in paramecia? in the process of digestion. Use the Paramecia ingest food Problem-Solving Lab on this page to Extension Process Skills particles and enclose explore how a paramecium digests Figure 19.6 A Spores of Plasmodium enter the mosquito from Have students research the phy- them in food vacuoles. the food in a vacuole. observe and infer, interpret sci- Each food vacuole circulates in the cell as the food is digested The life cycle of infected human blood and produce a zygote. In A paramecium usually reproduces lum of the organism Trypanosoma entific illustrations, recognize by enzymes that enter the vacuole. Digested nutrients are Plasmodium involves the mosquito’s gut, the zygote develops and cruzi. Ask them to draw and label cause and effect absorbed into the cytoplasm. asexually by dividing crosswise and two hosts—mosqui- eventually releases cells called sporozoites. separating into two daughter cells, as toes and humans. this protist. L2 Teaching Strategies Analysis you can see in Figure 19.5. When- 1. Some digestive enzymes function best at high pH levels, ever their food supplies dwindle or Review pH. Inform students Zygote Gut wall P while others function best at low (more acidic) pH levels. their environmental conditions change, of mosquito Assessment that there are both liquid and Gametes 2. Congo red is a pH indicator dye; it is red when the pH is paramecia usually undergo a form of Knowledge Have students paper pH indicators. above 5 and blue when the pH is below 3 (very acidic). conjugation. In this complex process, identify the unrelated word in 3. Yeast cells that contain Congo red can be produced by two paramecia join and exchange Thinking Critically adding dye to the solution in which the cells are growing. each ofLS the following groups: genetic material. Then they separate, P 4. When paramecia feed on dyed yeast cells, the yeast is visi- amoeba, foraminiferan, Para- It varies. The pH in a food vac- Mosquito feeds ble inside food vacuoles. and each divides asexually, passing on mecium, radiolarian; pseudopodia, uole forming at the end of the on infected person 5. Examine the drawing above. The appearance of a yeast- its new genetic composition. cilia, oral groove, pellicle; dysen- gullet is above 5. As digestion filled food vacuole over time is indicated by the colored begins, the pH drops to below 3 Sporozoans: Parasitic protozoans tery, AIDS, sleeping sickness, circles inside the paramecium. Each arrow indicates move- Chagas disease.LS L2 and changes again as digestion ment and the passing of time. Protists in the phylum Sporozoa are progresses. As digestion nears Thinking Critically often called sporozoans because most completion, the pH increases What happens to the pH in the food vacuole over time? produce spores. A spore is a repro- until it is above 5 again. There are Explain what sequence of digestive enzymes might function ductive cell that forms without fertil- Sporozoites 4 Close many digestive enzymes involved in a paramecium. ization and produces a new organism. in Paramecium digestion, and they All sporozoans are parasites. They Activity live as internal parasites in one or more Human host work at acidic and basic pHs. D The blood cells rupture, hosts and have complex life cycles. D Logical-MathematicalP Make releasing both toxins Magnification: 300 five sets of ten index cards Sporozoans are usually found in a part and new spores that B Sporozoites enter the of a host that has a ready food supply, infect more red blood C The sporozoites reproduce asexually B with one of the following words Assessment C mosquito’s salivary gland, Figure 19.5 such as an animal’s blood or intestines. cells and multiply. in the human’s liver, forming spore- on each card: locomotion, cilia, Performance Give stu- and are injected into the A paramecium is Plasmodium, members of the sporo- like cells that enter the human’s red pseudopodia, flagella,LS sarcodines, dents liquids with different pHs. mosquito’s human host. dividing into two zoan genus, are organisms that cause blood cells and multiply rapidly. asexual reproduction, cyst, micro- Have them use pH paper to find identical daughter cells. the disease malaria in humans and nucleus, spore, sexual reproduc- which liquids match the pH in other mammals and in birds. tion. Give a set of cards to each of Paramecium’s food vacuole at the Section Assessment five student groups, telling them start and end of digestion. Use Sporozoans and malaria Understanding Main Ideas Thinking Critically to logically sequence the cards the Performance Task Assessment Throughout the world today, more and then explain their sequences. List for Carrying Out a Strategy 1. Describe the characteristics of the organisms 5. What role do contractile vacuoles play in helping than 300 million people have malaria, called protists. Then compare the characteristics freshwater protozoans maintain homeostasis? L2 and Collecting Data in PASC, a serious disease that usually occurs in of the four major groups of protozoans. How is p. 25. L2 ELL places that have tropical climates. The each group of protozoans animal-like? SKILL REVIEWEVIEW Plasmodium that mosquitoes transmit 2. How do amoebas obtain food? 6. Sequencing Trace the life cycle of a Plasmodium ResourceResource to people cause human malaria. As 3. Explain any differences that exist between cili- that causes human malaria. Identify all forms of you can see in Figure 19.6, malaria- ates and flagellates. the sporozoan and the role each plays in the ManagerManager P 4. What makes a sporozoan different from other disease. For more help, refer to Organizing 3 Assess causing Plasmodium live in both protozoan groups? Information in the Skill Handbook. Reinforcement and Study humans and mosquitoes. Guide, p. 83 Check for Understanding P L2 Content Mastery, p. 94 L1 Visual-SpatialP 524 PROTISTS Have students 19.1 THE WORLD OF PROTISTS 525 make aLS concept map show- ing Kingdom Protista’s three sub- BIOLOGYIOLOGY JOURNAL LS groups. Ask them to expand their Resource Manager Section Assessment maps toLS include the four proto- Malaria and Sickle-Cell Anemia zoan phyla. L2 1. Protists are eukaryotes without tissues. 4. All are parasitic, many produce spores, P Critical Thinking/Problem Solving, Linguistic Have students use refer- Protozoans are unicellular, heterotrophic and some cannot move. p. 19 L3 ences to report about the correlation protists. Rhizopods have pseudopodia, 5. Contractile vacuoles pump out excess Laboratory Manual, pp. 133-136 L2 between the genetic disease sickle-cell Ciliophorans have cilia, and flagella pro- water that enters the cell by osmosis. P anemia and the protist disease malaria. P pel Mastigophorans. Sporozoans are par- 6. Student answers should include the infor- LS They should include the evolutionary sig- asites. mation in Figure 19.6. Both the human nificance of such a relationship. L3 2. Pseudopodia entrap prey. and mosquito hosts and the forms that P P 3. Flagellates have long, whiplike flagella. Plasmodium take in each host should be LS 524 LS Ciliates have many short, hairlike cilia. distinquished. 525 P LS LS P

LS LS SECTION PREVIEW Euglenoids: Autotrophs Section 19.2 and heterotrophs Observing 2 Teach Objectives Section MiniLab 19-2 Compare and contrast Hundreds of species of euglenoids the variety of plantlike (yoo GLEE noydz) make up the phy- Going on an Algae Hunt Pond water may be teeming with protists. 19.2 Algae: Plantlike Protists MiniLab 19-2 Prepare lum Euglenophyta. Euglenoids are organisms. Some are macroscopic organisms, but the majority P Explain the process unicellular, aquatic protists that have are microscopic. Some may be heterotrophs, and others of alternation of Purpose both plant and animal characteristics. autotrophs. How can you tell them apart? Key Concepts generations in algae. Students will examine pond water Vocabulary Unlike plant cells, they lack a cell wall Procedure In this section, the diversity of ach time you inhale, you made of cellulose. However, they do for evidence of algae. algae is explored by focusing on thallus ! Copy the data table. LS colony breathe in oxygen, much of have a flexible pellicle made of pro- Process Skills the characteristics and adapta- fragmentation which is being produced by tein that surrounds the cell mem- Data Table alternation of E apply concepts, classify, compare tions of members of the six algae generations plantlike protists. The algae are brane. Euglenoids are plantlike in DiagramMotile/Nonmotile Unicellular/Multicellular and contrast, observe and infer phyla. Finally, alternation of gen- gametophyte important in the world of living that most have chlorophyll and pho- erations in algae is discussed. sporophyte things. Just about every liv- tosynthesize. However, they are also Teaching Strategies ing thing depends either animal-like because, when light is not Collect pond water or scrape available, they can ingest food in ways Planning directly or indirectly @ Place a drop of pond water onto a glass slide and add a algae from the inside of a fish that might remind you of some pro- Collect pond water or fish tank on these protists for coverslip. CAUTION: Use caution when working with a tank and stir into water. tozoans. In other words, euglenoids scum for MiniLab 19-2. oxygen and food. microscope, glass slides, and coverslips. Remind students to wear a lab can be heterotrophs. In Figure 19.7, Buy algae for students to taste. # Observe the pond water under low magnification of your apron, gloves, and goggles, to you can see a typical euglenoid. microscope, and look for algae that may be present. Algae handle slides carefully, and to Euglenoids might also remind you from a pond will usually be green or yellow-green in color. wash their hands after their work. of protozoans because they have one $ Diagram several different species of algae in your data Kelp forest (above) or more flagella to move. They use table and indicate if each is motile or nonmotile. Indicate Expected Results 1 Focus and algae growing in a if the algae are unicellular or multicellular. freshwater pond (inset) their flagella to move toward light or Students will find many algae. food. In the BioLab at the end of this Bellringer Analysis Analysis chapter you can learn more about 1. What characteristic distinguished algae from any proto- Before presenting the lesson, how a euglenoid responds to light. zoans that may have been present? 1. Algae are green in color. display Section Focus Trans- 2. Explain how the characteristic in question 1 categorizes 2. Autotrophs contain chloro- parency 46 on the overhead pro- Diatoms: The golden algae algae as autotrophs. phyll for photosynthesis. jector and have students answer Diatoms (DI uh tahmz), members of 3. Did you observe any relationship between movement and 3. The smaller the algae the the accompanying questions. What Are Algae? estimated that algae produce more the phylum Bacillariophyta, are uni- size? Explain your answer. more likely they are motile. than half of the oxygen generated by L1 ELL cellular photosynthetic organisms with Photosynthesizing protists are Earth’s photosynthesizing organisms. called algae. All algae contain up to Although multicellular algae may Assessment Figure 19.7 four kinds of chlorophyll as well as look like plants because they are Notice the eyespot in this Euglena gracilis. It Performance Have stu- TransparencyP 46 Giant Kelp SECTION FOCUS other photosynthetic pigments. large and sometimes green, they have Nucleus Use with Chapter 19, shades a light-sensitive receptor that helps E. dents use fertilizers to aid algal Section 19.2 These pigments produce a variety of no roots, stems, or leaves. Use the Chloroplast gracilis orient itself toward light. growth. Use the Performance Pacific sardines colors in algae, including purple, MiniLab on the next page to observe Task Assessment List for Carry- rusty-red, olive-brown, yellow, and some algae. Mitochondrion ing Out a Strategy and Collecting golden-brown, and are a way of clas- LS Data in PASC, p. 25. L2 ELL sifying algae into groups. P Eyespot Algae include both unicellular and Diversity of Algae Sea star Cabezon fish multicellular organisms. The photo- Algae are classified into six phyla. The BioLab at the DESIGN Brittle synthesizing unicellular protists, Three of these phyla—the eugle- end of the chapter OUR OWN star YO OP N known as phytoplankton (fite uh noids, diatoms, and dinoflagellates— can be used at this LS PLANK tun), are so numerous that include only unicellular species. point in the lesson. Flagellum they are one of the major producers However, in the other three phyla, Pellicle

Hermit crab P Rock crab of nutrients and oxygen in aquatic which are the green, red, and brown LS ecosystems in the world. It’s been algae, most species are multicellular. Contractile vacuole Magnification: 525 1 The large plantlike organism in the picture is giant kelp, a type Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. of protist called a brown alga. What role does the kelp play in this ecosystem?

2 How might the loss of the kelp affect this ecosystem? 526 PROTISTS 527 BIOLOGY: The Dynamics of Life SECTION FOCUS TRANSPARENCIES LS VIDEODISC BIOLOGYIOLOGY JOURNAL PROJECT STV: The Cell Resource Manager Magnified View of Protozoans and Algae Culturing Euglena overnight. Add 100 mL of a Euglena culture Euglenas (1) BioLab and MiniLab Worksheets, Naturalist Have students prepare Kinesthetic Have students establish a you purchased. Students can maintain the cul- p. 90 L2 a table that compares and con- culture of Euglena in the following ture in a well-lit area without direct sunlight !7QÉ.+" Section Focus Transparency 46 and trasts protozoans and algae. Suggest way. Add 20 rice grains and 5 mL skim milk while they design an experiment to deter- Master L1 ELL that they use the headings Similarities to 1 L of spring water. Boil for 5 minutes on mine how the numbers of Euglena change and Differences. The rows can include a hot plate in a glass container. Remind the over time. After getting your approval for P topics such as Cell organization, Nutri- students to wear heat protective gloves or their designs, ask the students to carry out P P tion, and Cell structures. L2 use tongs to lift heated objects. Add 3 L of their procedures. L3 ELL COOP LEARN 526 spring water and allow the mixture to cool 527 P P LS LS P LS LSP P LS P LS LS LS LS Using Science Terms Assessment (KER uh teen oydz) that usually give Figure 19.10 Skill Have the students them a golden-yellow color. The food Red tides, such as the one shown Tell students that the prefix dino that diatoms make is stored as oils here (a), are often caused by means “whirling” and the suffix observe, draw, and label prepared dinoflagellates such as this one slides of Euglena gracilis. Then, rather than starch. These oils give called Gonyaulax (b). flagellate means “whip.” Ask them ask them to estimate the size of fishes that feed on diatoms an oily why the name dinoflagellates is taste. They also give diatoms buoy- appropriate for these algae. They the organism, using the Skill a Handbook if they need help. ancy so that they float near the surface spin as their flagellas propel them where light is available. b L2 through water. L1 When diatoms reproduce asexu- ally, the two halves of the box sepa- Concept Development Reinforcement Magnification: 1500 rate; each half then produces a new Visual-Spatial Have students Figure 19.8 half to fit inside itself. This means Describe coral as a heterotroph make a concept map that Diatom shells have shells composed of silica. They are that half of each generation’s off- and ask students to explain the shows how the six algae phyla are many shapes. abundant in both marine and freshwa- spring are smaller than the parent role of dinoflagellates and coral related. Ask them to use the fol- ter ecosystems, where they are a large cells. When diatoms are about one- when they live symbiotically. P lowing terms: plantlike protists, component of the phytoplankton. quarter of their original size, they Dinoflagellates make food for the autotrophic, unicellular, mostly The delicate shells of diatoms, like reproduce sexually by producing corals, and the coralP reef helps safe- multicellular, diatoms, eugle- those you see in Figure 19.8, might gametes that fuse to form zygotes. guard dinoflagellates from predators. Magnification: 75 noids, dinoflagellates, green remind you of boxes with lids. Each The zygote develops into a full-sized algae,LS brown algae, red algae. species has its own unique shape, diatom, which will divide asexually When diatoms die, their shells sink free-living species are biolumines- Reinforcement decorated with grooves and pores. for a while. You can see both the to the ocean floor. The deposits of cent, which means that they emit Have them share their maps on Check that studentsLS know the Figure 19.9 Diatoms contain chlorophyll as well asexual and sexual reproductive diatom shells—some of which are light. overhead transparencies. L2 Diatoms reproduce as other pigments called carotenoids processes of diatoms in Figure 19.9. millions of years old—are dredged or Several species of dinoflagellates meaning of shellfish, biolumines- asexually for several mined, processed, and used as abrasives produce toxins. One toxin-producing cent, and toxins. Discuss why the Activity generations before in tooth and metal polishes, or added dinoflagellate, Pfiesteria piscicida, that term shellfish is a misnomer. reproducing sexually. Kinesthetic Have students to paint to give the sparkle that makes some North Carolina researchers Shellfish are not classified as fishes, prepare wet mounts of dia- pavement lines more visible at night. discovered in 1988 has caused a num- but as arthropods (shrimp and crabs) tomaceous earth and diagram the ber of fish kills in the coastal areas of or mollusks (clams and squid). Dinoflagellates: The diatoms’ shapes. For a source of North Carolina. P spinning algae diatoms, scrape the inside of a fish Mitosis Another toxic species, Gonyaulax tank. Remind students to handle Dinoflagellates (di nuh FLAJ uh catanella, produces an extremely P microscopes, slides, and coverslips layts), members of the phylum strong nerve toxin that can be lethal. Dinoflagellata, have cell walls that In the summer, these organisms may carefully. L2 ELL LS Wall formation are composed of thick cellulose become so numerous that the ocean VIDEODISC around cell plates. They come in a great variety takes on a reddish color as you can The Infinite Voyage LS of shapes and styles—some even see in Figure 19.10. This population Asexual reproduction Secrets from a Frozen P resemble helmets, and others look explosion is called a red tide. In some World Meiosis like suits of armor. red tides, there can be as many as 40 The Antarctic Peninsula: Pack Ice Dinoflagellates contain chloro- to 60 million dinoflagellates per liter and Life Cycles (Ch. 6) VIDEODISC phyll, carotenoids, and red pigments. of seawater. Sexual reproduction 10 min. 30 sec. Biology:P LS The Dynamics They have two flagella located in The toxins produced during a red of Life grooves at right angles to each other. tide may make humans ill. During Protists (Ch. 12) The cell spins slowly as the flagella red tides, the harvesting of shellfish is !7_jJ" Disc 1, Side 2, 26 sec. Zygote beat. A few species of dinoflagellates usually banned because shellfish feed Effects of UV Radiation on LS live in freshwater, but most are on the toxic algae and the toxins con- Phytoplankton (Ch. 8) !8@Å" Gametes marine and, like diatoms, are a major centrate in their tissues. People who 4 min. 30 sec. component of phytoplankton. Many eat such shellfish risk being poisoned. Fusion of Sperm species live symbiotically with jelly- You can learn more about the causes !7s~D" gametes released fishes, mollusks, and corals. Some and effects of red tides in the

528 PROTISTS 19.2 ALGAE: PLANTLIKE PROTISTS 529

VIDEODISC MEETING INDIVIDUAL NEEDS PortfolioPortfolio STV: The Cell: Diatom, Magnified 300 Times Visually Impaired Algal Names Kinesthetic Allow students to hold a Linguistic Although algae are VIDEODISC petri dish and explain that its halves often called “seaweed, scum, and !7QÄV," P fit together in a manner similar to that of STV: The Cell Diatom, Magnified 3,000 Times sea moss,” none of these terms are scien- a diatom’s halves. L1 ELL tifically correct. Have students find the Dinoflagellates Red Tide meaning of each term and then explain !7QÄ`#" P LS why it is scientifically incorrect. L2 !7QÑV&" !7QÑ`'" P ELL P 528 529 LS P LS LS P P LS

LS LS Quick Demo Problem-Solving Lab on the next page. keep their bodies floating near the mals that live in the tropical rain for- Quick Demo Recognizing Cause surface, where light is available. est canopy. Problem-Solving Lab 19-2 and Effect Purchase preserved brown and Red algae The largest and most complex of Green algae can be unicellular, Allow students to feel the tex- red algae for class display. If Red algae, members of the phylum brown algae are kelp. In kelp, the colonial, or multicellular in organiza- ture of agar in a petri dish. P Why is the number of red possible, buy some edible algae tides increasing? Scientists Rhodophyta, are multicellular marine thallus is divided into the holdfast, tion. As you can see in Figure 19.12, Then, display an ingredient for students to taste. have been aware of red tide seaweeds. The body of a seaweed, as stipe, and blade. The holdfasts Chlamydomonas is a unicellular and label from an ice cream carton poisoning of birds, fishes, and well as that of some plants and other anchor kelp to rocks or the sea bot- flagellated green alga. Spirogyra is a that lists alginate, agar, or car- mammals such as whales and organisms, is called a thallus and tom. Some giant kelps may grow up multicellular species that forms slender rageenan, a protein found in LS humans for years. Could the rise lacks roots, stems, or leaves. Red to 60 meters long. In some parts of filaments. Volvox is a green alga that in red tide poisoning be related red algae. Discuss why algal algae use structures called holdfasts to the world, such as off the California can form a colony, a group of cells to human activities? products are used in ice cream Problem-Solving Lab 19-2 attach to rocks. They grow in tropical coast, giant kelps form dense, under- that lives together in close association. Problem-Solving Lab 19-2 and agar. Encourage students P Analysis A sperm whale’s carcass waters or along rocky coasts in cold water forests. These kelp forests are A Volvox colony is composed of WORD Origin to think of other products The following events are associated with the appearance water. You can see a red alga in rich ecosystems and provide a wide hundreds, or thousands, of flagellated thallus P Purpose of red tides. that might have a similar alga Figure 19.11. variety of marine organisms with cells arranged in a single layer form- From the Greek A The dinoflagellate toxin that causes illness and sometimes Students will analyze real-life In addition to chlorophyll, red their habitats. ing a hollow, ball-shaped structure. word thallos, mean- ingredient. L1 death in humans accumulates in the body tissues of shell- events associated with red tides. ing “green shoot.” LS fish, such as clams and oysters. algae also contain photosynthetic The cells are connected by strands of Green algae A thallus is a plant B Within five weeks, 14 humpback whales died on beaches pigments called phycobilins. These cytoplasm, and the flagella of individ- Process Skills without stems, LS in Massachusetts. The whales’ stomachs contained mack- pigments absorb green, violet, and Green algae make up the phylum ual cells face outward. The flagella roots, or leaves. think critically, acquire informa- erel with high levels of dinoflagellate toxin. blue light—the only part of the light Chlorophyta. The green algae are can beat in a coordinated fashion, Assessment tion, draw a conclusion, recog- C Between 1976 and 1986, the human population of Hong spectrum that penetrates water below the most diverse algae, with more spinning the colony through the Portfolio Have students Kong increased sixfold, and its harbor had an eightfold nize cause and effect depths of 100 m. Therefore, the red than 7000 species. The major pig- water. Small balls of daughter increase in red tides. Human waste water was commonly make a flowchart of the life cycle emptied into the harbor. algae can live in deep water where ment in green algae is chlorophyll, colonies form inside the large sphere. of Ulva and include the terms: Teaching Strategies D Studies show that red tides are increasing world wide. most other seaweeds cannot thrive. but some species also have yellow The wall of the large colony will alternation of generations, game- P Have students work in small E An algal bloom occurs when algae, using sunlight and pigments that give them a yellow- eventually break open and release the tophyte, sporophyte, mitosis, abundant nutrients, increase rapidly in number to hun- Brown algae P groups, discussing each event green color. Most species of green daughter colonies. meiosis, zygote, and gamete. L2 dreds of thousands of cells per milliliter of water. About 1500 species of multicellular algae live in freshwater, but some live Green algae reproduce both asexu- thoroughly. P Have groups share answers. Thinking Critically brown algae make up the phylum in the oceans, in moist soil, on tree ally and sexually. For example, 1. Which statement above provides evidence that supports Phaeophyta. Almost all of these trunks, in snow, and even in the fur Spirogyra reproduces asexually by frag- LS Thinking Critically each of the following ideas. Explain each answer. species live in salt water along rocky of sloths—large, slow-moving mam- mentation. During fragmentation, an LS 1. a. Dinoflagellate poisons flow through the food chain. coasts in cool areas of the world. a. A or B—Toxins accumulate b. Dinoflagellates are autotrophs. Brown algae contain chlorophyll as Figure 19.12 b LS in shellfish that humans eat; c. There is a correlation between human activities and well as a yellowish-brown carotenoid Chlamydomonas is a unicellular mackerel eat dinoflagellates algae growth. P called fucoxanthin, which gives them species of green algae (a), while c CD-ROM 2. All animals equally tolerate dinoflagellate toxins. Which and whales eat the mackerel. their brown color. Many species of Spirogyra is a multicellular form Biology: The Dynamics statement contradicts this idea? Explain your answer. b. E—Autotrophs use sun- brown algae have air bladders that (b). The wall of a Volvox colony of Life contains hundreds of cells (c). The light and nutrients to grow. Video: Kelp Forests, Disc 3 c. C—Human population smaller balls inside the sphere are daughter colonies. VIDEODISC LS growth correlates with the Figure 19.11 Biology: The Dynamics frequency of red tides. This Coralline alga is only one of of Life 2. A or B—Shellfish are not about 4000 species of red algae. a Some species are popular foods in Kelp Forests (Ch. 13) affected by dinoflagellate tox- Japan and other countries. Disc 1, Side 2 ins, but humans are; mackerel !8JÇ" 26 sec. do not die from dinoflagellate toxins, but whales do. Magnification: 14

Assessment Magnification: Portfolio Have students 1400 diagram dinoflagellates they ob- serve on prepared slides. Use the VIDEODISC 530 PROTISTS Magnification: 1250 531 Performance Task Assessment STV: The Cell List for Scientific Drawing in Volvox With PASC, p. 55. L1 MEETING INDIVIDUAL NEEDS Chloroplasts Cultural Diversity Resource Manager Algae Harvesting in Japan used in Japanese cooking is Porphyra, a red Visually Impaired !7QÑB$" Inform students that people in many areas alga commonly called nori. Since the seven- Kinesthetic Have students make a Tech Prep Applications, p. 27 L2 of the world, particularly Asia, eat some teenth century, the Japanese have harvested textural circle graph that shows the Laboratory Manual, pp. 137-140 L2 algae. Point out that algae contain nutrients, nori from Tokyo Bay. Have students research number of species in each algal phylum. such as protein, and many vitamins and min- how the Japanese harvest algae. Bring in Provide the following data: Euglenoids = 800, Diatoms = 10 000, Dinoflagellates = erals. Algae are eaten fresh and boiled or some Japanese foods that contain algae for P 2000, Red algae = 4000, Brown algae = P fried in many Asian recipes. One edible algae the class to sample. L3 1500, Green algae = 7000. L2 530 P 531 LS P LS P LS LS P LS

LS SECTION PREVIEW 3 Assess Section 19.3 Male Section Objectives Check for Understanding gametophyte Contrast the cellular differences and life Have students describe briefly 19.3 Slime Molds, Water Molds, cycles of the two types three unicellular and three multi- of slime molds. Prepare cellular algae phyla. L2 and Downy Mildews Discuss the economic Gametophyte (n) importance of the Key Concepts downy mildews and Gametophyte (n) Female water molds. This section presents the charac- Reteach gametophyte hen you walk through the Vocabulary teristics of funguslike protists. Have the class develop a concept woods, you might notice a Figure 19.13 spot of color on a fallen log. plasmodium The phyla of plasmodial slime map of the material in this chap- Sporophyte (2n) W In the life cycle of Spore Gamete Gamete Turning the log over, you uncover a molds, cellular slime molds, and ter’s first two sections. L2 the sea lettuce, the water molds and downy mildews generations alternate glistening mass of yellow-orange P between haploid Fertilization slime that fans out over the log. are described. Finally, the origin Extension n (gametophyte) and Zygote What you’ve found is a slime mold, of protists is discussed. Ask students to compile a list of diploid (sporophyte). Meiosis one of a variety of funguslike protists. foods that contain algae. L2 Both fungi and plants Slime molds, along with water molds Planning also alternate genera- Spore 2n 2n 2n LS tions. n and downy mildews, obtain energy by Obtain meat, string, and an P decomposing organic materials, aquarium for the Quick Demo. Assessment and play an important role Knowledge Make six line individual breaks up into pieces and nation of generations. An organism in recycling nutrients in drawings showing an alga from each piece grows into a new individual. that has this pattern alternates many ecosystems. Green algae, and some other types between a haploid and a diploid gen- each of the six phyla. Give stu- of algae, have a complex life cycle. eration. 1 Focus LS P A plasmodial slime dents sets of the drawings and ask This life cycle consists of individuals The haploid form of the organism them to list three facts or ideas mold that is feeding Bellringer that alternate between producing is called the gametophyte because it (above) and repro- about each alga. L2 reproductive cells called spores and produces gametes. The gametes fuse ducing (inset) Before presenting the lesson, producing gametes. to form a zygote from which the display Section Focus Trans- LS diploid form of the organism, which parency 47 on the overhead pro- Alternation of is called the sporophyte, develops. jector and have students answer 4 Close Certain cells in the sporophyte the accompanying questions. Generations undergo meiosis. Eventually, these L1 ELL Discussion Questions The life cycles of some algae and cells become haploid spores that can Have each studentP prepare three all plants have a pattern called alter- develop into a new gametophyte. Look What are Funguslike and fungi and are classified by the questions about algae. Collect the Protists? way they reproduce. Water molds and downy mildews make up the TransparencyP 47 Slime Molds SECTION FOCUS questions and have the students Use with Chapter 19, Section 19.3 answer them. L1 Certain groups of protists, the third phylum of funguslike protists. LS Section Assessment slime molds, the water molds, and Although funguslike protists are not the downy mildews, consist of organ- an everyday part of human lives, Understanding Main Ideas Thinking Critically isms with some funguslike features. some disease-causing species damage 1. In what ways are algae important to all living 5. Use a table to list the reasons why euglenoids LS Recall that fungi are heterotrophic vital crops. Amoeba-like cells things on Earth? should be classified as protozoans and also as P Spore-filled capsule 2. Give examples that show why the green algae algae. organisms that decompose organic are considered to be the most diverse of the six materials to obtain energy. Like VIDEODISC KILL EVIEW phyla of algae. SKILL REVIEW fungi, the funguslike protists decom- Slime Molds Multicellular The Infinite Voyage 3. In what ways do the sporophyte and gameto- 6. Making and Using Tables Construct a table pose organic materials. Many slime molds are beautifully amoeboid mass The Living Clock, phyte generations of an alga such as Ulva differ listing the different phyla of algae. Indicate There are three phyla of fungus- colored, ranging from brilliant yellow LS P Circadian Rhythm and the from each other? whether they have one or more cells, their color, like protists. Two of these phyla con- or orange to rich blue, violet, and jet Biological Clock (Ch. 4) 4. Why are phycobilins an important pigment in and give an example of each. For more help, refer sist of slime molds. Slime molds have black. They live in cool, moist, shady 1 The pictures show some stages of the life cycle of a cellular red algae? to Organizing Information in the Skill Handbook. slime mold, a funguslike protist. During which part is the slime 5 min. characteristics of both protozoans places where they grow on damp, Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. mold animal-like? !7KVF" 2 Why might it be difficult to classify slime molds? LS 19.3 SLIME MOLDS, WATER MOLDS, AND DOWNY MILDEWS 533 BIOLOGY: The Dynamics of Life SECTION FOCUS TRANSPARENCIES 532 PROTISTS

MEETING INDIVIDUAL NEEDS ResourceResource Section AssessmentAssessment Resource Manager ManagerManager 1. They are producers of oxygen and the 5. Their chloroplasts are algaelike and their English Language Learners Linguistic Reinforce terms students Section Focus Transparency 47 and Reinforcement and Study primary autotrophs of many food chains. locomotion is protozoanlike. can use to recall the three groups Master L1 ELL Guide, pp. 84-85 L2 2. Chlamydomonas is a unicellular example. 6. Euglenophyta—one, green, euglena; Volvox is a colonial form. Ulva is a multi- Bacillariophyta—one, golden, diatom; of protists. For animal-like protists, use Basic Concepts Transparency 28 and cellular alga. Dinoflagellata—one, green, yellow, and unicellular, motile, and heterotroph. For Master L2 ELL 3. Haploid gametophytes form gametes red, dinoflagellate; Rhodophyta—many, plantlike protists, use photosynthetic, P autotroph, unicellular, and multicellular. and diploid sporophytes form spores. red, red seaweed; Phaeophyta—many, P 4. They can absorb the green, violet, and brown, brown seaweed; Chlorophyta— For funguslike protists, use heterotroph P 532 blue light that penetrates deep water. one or many, green, green algae. and decomposer. ELL 533 P LS LS PP P LS LS LSLS LS Reinforcement organic matter such as rotting leaves Figure 19.15 a 2 Teach Problem-Solving Lab 19-3 Predicting or decaying tree stumps and logs. The reproductive cycle Prepare an overview that illus- Problem-Solving Lab 19-3 Cells There are two major types of slime of a cellular slime mold trates the relationship between is complex (a). Single gather molds—plasmodial slime molds and the phyla Myxomycota and What changes occur during a slime mold’s life cycle? cells clump and form a Spores Cells feed, cellular slime molds. The plasmodial Amoebalike Acrasiomycota and Kingdom Problem-Solving Lab 19-3 Plasmodial slime molds undergo a number of different stages structure that resembles cells released grow, and divide P during their life cycle. The most visible stage is the plasmodial slime molds belong to the phylum a small garden slug (b). Protista. Purpose stage, where the organism looks like a slimy mass of material. Myxomycota, and the cellular slime Eventually, the clump The plasmodium changes into a reproductive stage that is molds make up another grouping, forms a stalked repro- Students will relate cell division microscopic and, therefore, less visible. ductive structure that Multicellular the phylum Acrasiomycota. amoeboid like Assessment to a slime mold’s life cycle. produces spores (c). Spore-filled LS Spores B Slime molds are animal-like during mass forms Performance Have each A capsule on a C much of their life cycle, moving about stalk forms Process Skills c student write two questions about and engulfing food in a way similar to slime molds. Divide the class into apply concepts, interpret scien- that of amoebas. However, like fungi, Reproductive pairs and have students quiz each tific illustrations, think critically slime molds make spores to repro- stages other. L1 D duce. Use the Problem-Solving Lab on The sluglike Teaching Strategies this page to learn more about the life structure Grow slime molds and have cycle of a slime mold. migrates The mass compacts students observe them with a and forms a E sluglike structure stereo microscope. F Plasmodial slime molds Review mitosis, meiosis, fertil- G Growth Plasmodial slime molds get their VIDEODISC ization, and spore formation. stages name from the fact that they form a VIDEOTAPE Analysis plasmodium (plaz MOHD ee um), a Thinking Critically Examine the life cycle of a plasmodial slime mold. The mass of cytoplasm that contains The Secret of Life P structures below the dashed line are diploid in chromosome many diploid nuclei but no cell walls On the Brink: Portraits of 1. mitosis—cell growth; meio- b number. Based on the diagram and your understanding of or membranes. This slimy, multinu- Modern Science sis—haploid gamete forma- mitosis and meiosis, answer the questions below. tion (gametes form at C) cleate mass, like the one you see in Thinking Critically Figure 19.14, is the feeding stage of !7@Z'ULA" 2. D—two gamete cells join; digesting them in food vacuoles. At 1. What cell process, mitosis or meiosis, takes place between the organism. The plasmodium LS CD-ROM C—cells with flagella; E—it that rate, a plasmodium would cross F and G? Explain why. Between A and B? Explain why. creeps like an amoeba over the sur- Biology: The Dynamics results from fertilization. 2. What letter best shows fertilization occurring? Motile your textbook page in eight hours. faces of decaying logs or leaves. of Life 3. growth stage—organisms use spores? An embryo? Explain why in each case. Some plasmodiums move at the rate A plasmodium may reach more 3. During which stage does the slime mold feed? Explain. Video: Slime Mold food to grow of about 2.5 centimeters per hour, than a meter in diameter and contain Magnification: 140 Disc 3 engulfing microscopic organisms and thousands of nuclei. However, when moisture and food become scarce in VIDEODISC Assessment its surroundings, a plasmodium Biology: The Dynamics Figure 19.14 transforms itself into many separate, their life cycle as an independent of Life Performance Have stu- The moving, feeding stalked, spore-producing structures. amoeboid cell that feeds, grows, and Slime Mold (Ch. 14) dents grow slime molds from pur- form of a plasmodial Meiosis takes place within these divides by cell division, as shown in WORD Origin slime mold is a multi- Disc 1, Side 2, 14 sec. chased spores. Use the Perform- structures and produces haploid Figure 19.15. When food becomes plasmodium ance Task Assessment List for nucleate blob of cytoplasm. spores, which the wind disperses. A scarce, these independent cells join From the Greek !8TÉ" Carrying Out a Strategy and spore germinates into either a flagel- with hundreds or thousands of others word plassein, Collecting Data in PASC, p. 25. lated or an amoeboid cell, or a to reproduce. Such an aggregation of meaning “mold,” L3 ELL and the Latin word gamete, that can fuse with another amoeboid cells resembles a plasmod- odium, meaning cell to form a zygote. The diploid ium. However, this mass of cells is “hateful.” One form zygote grows into a new plasmodium. multicellular—made up of many of a slime mold is ResourceResource individual amoeboid cells, each with a plasmodium. P ManagerManager Cellular slime molds a distinct cell membrane. Cellular P Unlike plasmodial slime molds, slime molds are haploid during their Concept Mapping, p. 19 L3 cellular slime molds spend part of entire life cycle. ELL LS Basic Concepts Transparency 534 PROTISTS 19.3 SLIME MOLDS, WATER MOLDS, AND DOWNY MILDEWS 535 29 and Master L2 ELL Reteaching Skills Trans- LS P parency 30 and Master Physarum polycephalum (Prepare subcul- 3. Design a way to determine if the Analysis P Alternative Lab Assessment L1 ELL tures two days in advance by cutting sec- organism moves or not. 1. Describe the slime mold’s appearance P Knowledge Write a paragraph tions from the culture, putting the pieces 4. Record your macroscopic observations. and behavior. Is it a plasmodial or cellu- Observing Slime Mold explaining if you observed the feeding or P on plastic agar plates that contain a few 5. Use a stereo microscope to observe the lar slime mold? yellow, bloblike, stringy, the reproductive stage of the slime mold. LS flakes of oat cereal moistened with distilled slime mold. Record your observations moves very slowly—plasmodium P LS Purpose Use the Performance Task Assessment P water.); stereo microscope about its microscopic appearance and 2. Describe the slime mold’s microscopic Allow students to observe a plasmodium- List for Writing in Science in PASC, LS behavior. appearance and behavior. Material type slime mold. Procedure p. 87. L2 LS Give students the following directions. 6. Wash your hands thoroughly when you flows within the slime mold, stops, then Materials 1. Wear a lab apron, gloves, and safety finish. Dispose of the slime mold as flows in the opposite direction. LS petri dish with plasmodium stage of LS goggles during this lab. your teacher directs. P 534 2. Observe the slime mold. 535

P LS

LS Quick Demo Water Molds and Connection at the end of the chapter, Figure 19.17 Assessment you can read about a downy mildew This fanlike diagram shows Rhizopods Visual-Spatial Tie string Downy Mildews called Phytophthora infestans that has the relationships of the dif- 11 500 species Knowledge Ask students Water molds and downy mildews ferent protist phyla on the to list several protozoanlike traits around a piece of meat affected the lives of many people by Geologic Time Scale. and suspend it in the water of are both members of the phylum destroying their major food crop. and several funguslike traits of the an aquarium. After several Oomycota. Most members of this funguslike protists. large and diverse group of funguslike days, remove the meat and Origin of Protists Chlorophytes Ciliates protists live in water or moist places. PROTISTS 7000 species Flagellates have students examine it both 2500 species 8000 species As shown in Figure 19.16, some feed How are the many different kinds macroscopically and with a on dead organisms and others are of protists related to each other and 4 Close stereo microscope and re-cord plant parasites. to fungi, plants, and animals? You can their observations. Have stu- Phaeophytes P Most water molds appear as fuzzy, see the relationships of protists to 1500 species Activity dents wear a lab apron and white growths on decaying matter. each other in Figure 19.17. Have students list five words disposable gloves. They resemble some fungi because Although taxonomists are now related to funguslike protists. Tell they grow as a mass of threads over a comparing the RNA and DNA of them that four words must be food source, digest it, and then these groups, there is little conclusive Rhodophytes LS 4000 species Sporozoans related to each other, and the absorb the nutrients. But at some evidence to indicate whether ancient 3900 species Visual Learning Bacillariophytes Euglenophytes fifth word must be unrelated. point in their life cycle, water molds protists were the evolutionary ances- 10 000 species 800 species Collect the lists. Copy some lists Figure 19.17 Review the rela- produce flagellated reproductive tors of fungi, plants, and animals or Dinoflagellates onto the chalkboard and, in each tionships among the different cells—something that fungi never do. whether protists emerged as evolu- 1000 species protist phyla shown in the figure. This is why water molds are classified tionary lines that were separate. case, have the class find the unre- as protists rather than fungi. Because of evidence from compara- lated word and describe how the One economically important tive RNA sequences in modern green remaining words are related. L2 member of the phylum Oomycota is algae and plants, many biologists 3 Assess a downy mildew that causes disease agree that ancient green algae were in many plants. In the Social Studies probably ancestral to modern plants. ResourceResource Animals Check for Understanding Acrasiomycotes ManagerManager 65 species Naturalist Have students Magnification: 40 Plants Figure 19.16 Reinforcement and Study compare and contrast the Water molds and downy mildews live in Guide, p. 86 L2 three funguslike protist phyla. moist places and cause both plant and Myxomycotes P Content Mastery, Ask them to explain why these animal diseases. 450 species pp. 93, 95-96 organisms are classified as pro- L1 tists and not fungi. L2 A The downy mildew Oomycotes Phytophthora 175 species Fungi infestans is LS Reteach killing this PRESENT CENOZOIC MESOZOIC PALEOZOIC PRECAMBRIAN potato plant. Naturalist Have student P groups prepare charts that compare and contrast the phyla Section Assessment Myxomycota, Acrasiomycota, and Understanding Main Ideas Thinking Critically P Oomycota. L2 COOP LEARN 1. Describe the protozoan and funguslike charac- 5. In what kinds of environments would you expect LSP teristics of slime molds. to find slime molds? Explain your answer. P 2. Why might some biologists refer to plasmodial Extension slime molds as acellular slime molds. (Hint: SKILL REVIEWEVIEW Visual-Spatial Have students Look in Appendix B for the origins of scientific 6. Observing and Inferring If you know that LS terms.) a plasmodium consists of many nuclei within a LS make flowcharts of the life 3. How could a water mold eventually kill a fish? single cell, what can you infer about the process cycles of Myxomycota and Acra- B The water mold growing LS on this insect is decompos- 4. How does a plasmodial slime mold differ from a that formed the plasmodium? For more help, siomycota organisms and include cellular slime mold? refer to Thinking Critically in the Skill Handbook. P ing the insect’s tissues and the chromosome number for absorbing the nutrients. each stage. L3

536 PROTISTS 19.3 SLIME MOLDS, WATER MOLDS, AND DOWNY MILDEWS 537 ResourceResourceLS Manager IOLOGYIOLOGY OURNAL Manager Internet Address Book B J P Section Assessment Basic Concepts Trans- Origin of Protists parency 30 and Master Note Internet addresses 1. They are protozoanlike in that at differ- 4. Plasmodial slime molds feed as a multinu- Linguistic Have students write a ent stages they have flagella and the cleated plasmodium, but cellular slime L2 ELL that you find useful in paragraph offering their views on the space below for quick reference. P ability to move like amoebas. They are molds feed as amoeboid cells. LS the origin of and relationships among funguslike in that they produce spores, 5. Slime molds should live in moist environ- protists. L3 and many are saprophytic decomposers. ments where the moisture would prevent P 2. The plasmodium is a mass of cytoplasm dehydration and provide the conditions LS containing many nuclei but no cell walls their food supply needs to thrive. or membranes that separate cells. 6. The process suggests mitosis without cell 536 P 3. The mold digests its tissues. division. 537 LS P

LS LS DESIGN DESIGN D DESIGN D YOUR OWN D YOUR OWN YOUR OWN How do Paramecium and PPLANLAN THETHE EEXPERIMENTXPERIMENT Euglena respond to light? 1. Decide on an experimental pro- 6. To mount drops of Paramecium P cedure that you can use to test culture and Euglena culture on Time Allotment your hypothesis. microscope slides, use a tooth- embers of the genus Paramecium are ciliated protozoans— 2. Record your procedure, step- pick to place a small ring of AANALYZENALYZE ANDAND CCONCLUDEONCLUDE One class period M unicellular, heterotrophic protists that move around in search of by-step, and list the materials methyl cellulose on a clean you will be using. microscope slide. Place 1. Answers may vary. Data must Process Skills LS small food particles. Euglena are unicellular algae—autotrophic protists 3. Design a data table in which to a drop of Paramecium or be used to either support or observe and infer, experiment, that usually contain numerous chloroplasts. In this BioLab, you’ll record your observations and Euglena culture within reject student hypotheses. form a hypothesis, identify and investigate how these two protists respond to light in their environment. results. this ring. Place a coverslip 2. Euglena are attracted to light. control variables Check the Plan over the ring and cul- Paramecium avoid bright Discuss all the following points ture. The thick light. Euglena need light to Safety Precautions with other group members to deter- consistency of PPREPARATIONREPARATION make food. Heterotrophic, Remind students to be careful mine your final procedure. methyl cellulose Paramecium can find food in when working with microscopes, Problem Possible Materials 1. What variables will you have to should slow down dim and dark places. slides, and coverslips and to use Do both Paramecium and Euglena Euglena culture measure? the organisms for special care when viewing a slide respond to light and do they respond Paramecium culture 2. What will be your control? easy observation. 3. Most autotrophs show a posi- under high power. Have students in different ways? Among the mem- microscope 3. What will be the shape of the 7. Make preliminary observations tive response to light whereas wash their hands after finishing bers of your group, decide on one microscope slides light-controlled area(s) on your of swimming Paramecia and most heterotrophs show a the lab. type of protist activity that would dropper microscope slide? Euglena. Then think again negative response. constitute a response to light. methyl cellulose 4. Decide who will prepare mate- about the observation times rials, make observations, and that you have planned. Maybe Error Analysis PPREPARATIONREPARATION coverslips Hypotheses metric ruler record data. you will decide to allow more Advise students to do several tri- Decide on one hypothesis that you 5. Make sure your teacher has ap- or less time between your To demonstrate how Euglena index cards als for each organism. Ask them will test. Your hypothesis might be proved your experimental plan observations. and Paramecium respond to scissors why this is important. that Paramecium will not respond to toothpicks before you proceed further. 8. Carry out your experiment. light, cover a test tube con- light and Euglena will respond, or taining Euglena with black that Paramecium will move away from Safety Precautions Assessment paper containing a narrow, light and Euglena will move toward Always wear goggles in the lab. slitlike opening. Leave the Portfolio Have students light. Use caution when working with a AANALYZENALYZE ANDAND CCONCLUDEONCLUDE tube in bright light for 12 microscope, glass slides, and cover- write an evaluation of what they Objectives hours and then remove the slips. Wash your hands with soap and 1. Checking Your Hypothesis Did learned in this investigation. Use paper. Where the slit was In this BioLab, you will: water immediately after working with your data support your hypothesis? Going Further the Performance Task Assessment Prepare located, students should ob- slides of Paramecium and protists and chemicals. Why or why not? List for Writing in Science in serve a green band of Euglena. Euglena cultures and observe swim- 2. Comparing and Contrasting Project You may want to extend this experi- PASC, p. 87. L2 Skill Handbook ment by varying the shapes or relative sizes of Cover half of a test tube con- ming patterns in the two organ- Compare and contrast all the re- isms. Use the Skill Handbook if you need light and dark areas or by varying the bright- taining Paramecium with black sponses of the Paramecium and ness or color of the light. In each case, make Compare how these two different additional help with this lab. Going Further paper, place the tube on its Euglena to both light and darkness. hypotheses before you begin. Keep your data protists respond to light. side in bright light for 12 What explanations can you suggest in a notebook, and draw up a table of your Students may wish to test the results at the end of your investigations. hours. Paramecium should con- for their behavior? response of these protists to gregate in the covered side. 3. Making Inferences Can you use To find out more about other factors, such as different your results to suggest what sort protists, visit the Glencoe concentrationsP of salt solutions. Possible Hypotheses of responses to light and darkness Science Web Site. www.glencoe.com/sec/science L3 ELL If Paramecium are attracted to you might observe using other het- light, then they will move to the erotrophic or autotrophic protists? light zone on a glass slide con- LS P taining both light and dark zones. 538 PROTISTS 19.3 SLIME MOLDS, WATER MOLDS, AND DOWNY MILDEWS 539 If Euglena are attracted to P light, then they will move to the PLANLAN THETHE EXPERIMENTXPERIMENT light zone on a glass slide con- P E Resource Manager taining both light and dark zones. LS Teaching Strategies Possible Procedures Data and Observations BioLab and MiniLab Worksheets, Provide time for students to observe the Index cards can provide a light and dark Data should indicate that Euglena are LS pp. 91-92 organisms’ size, speed, and mobility under a microscope zone. Cut the cards to fit over attracted to light; Paramecium are not. L2 microscope before they begin. part of the coverslip. Students should Have students use low power to observe focus on the edge of the card to observe Paramecium (a 5 objective works best) and each organism’s direction of movement. high power to observe Euglena. If possible, use coverslips (22 30 mm or Advise students that they must count 22 40 mm) that cover a large area. 538 organisms quickly. Prepare or purchase methyl cellulose. 539 P

LS Social Studies Social Studies Chapter 19 Assessment Chapter 19 Assessment Connection Connection The Irish Potato P Famine SSUMMARYUMMARY Main Ideas Purpose Section 19.1 Main Ideas Vocabulary Summary statements can be used by Students will learn why a balance Kingdom Protista is a diverse group of living algae (p. 519) students to review the major con- A funguslike protist known as Phytophthora Oomycota. In addition, the wind probably widely The World things that contains animal-like, plantlike, and asexual reproduction between humans and the organ- (p. 521) cepts of the chapter. LS dispersed the P. infestans spores, infecting the funguslike organisms. isms in their environment is infestans causes a disease called potato blight. of Protists ciliate (p. 522) important. Between the years 1845–1847, the disease leaves and stems of mature potato plants. The Some protists are heterotrophs, some are auto- flagellate (p. 522) Using the Vocabulary damaged or totally destroyed the Irish potato spores also washed into the soil and infected the trophs, and some get their nutrients by decom- protozoan (p. 519) underground stems, or tubers, of the potatoes. To reinforce chapter vocabulary, use Teaching Strategies crop—a primary food source for about one-third posing organic matter. pseudopodia (p. 520) The potato blight damaged the Irish potato crop spore (p. 524) the Content Mastery Booklet and Amoebas move by extending pseudopodia. The Ask what influences other than of the Irish population at the time. A severe in 1845, and it destroyed nearly the entire potato sporozoan (p. 524) flagellates use one or more flagella to move. the activities in the Interactive Tutor famine might lead to mass emi- seven-year famine resulted. crop in one week’s time in the summer of 1846. The beating of cilia produces cilliate movement. for Biology: The Dynamics of Life on grations? Climatic changes, partic- Sporozoans live as parasites and produce spores. the Glencoe Science Web Site. ularly droughts, political upheavals, Mass emigration of the Irish Many Irish www.glencoe.com/sec/science wars, economic devastation. he potato was first grown in Ireland in the people starved in the years that followed. Many Tlate 1500s and within 200 years was a wide- others emigrated from Ireland. By 1855, the Section 19.2 Main Ideas Vocabulary Connection to Biology spread food crop. Potatoes grew well in the tem- population of Ireland had fallen from about eight Algae are unicellular and multicellular photo- alternation of All Chapter perate, rainy Irish climate. They were not vul- generations (p. 532) With fewer infestations of Phyto- million to four million. The Irish immigrated Algae: Plantlike synthetic autotrophs. Unicellular species include nerable to many diseases, needed no processing, primarily to four countries, the United States, colony (p. 531) Assessment phthora infestans, it is more diffi- the euglenoids, diatoms, dinoflagellates, and and were nutritious. In addition, most Irish peo- Protists fragmentation (p. 531) questions and answers have been England, Canada, or Australia. The large num- some green algae. Multicellular species include cult to determine its evolutionary ple were tenant farmers with farms averaging gametophyte (p. 532) validated for accuracy and suitabil- bers of immigrants greatly affected the social red, brown, and green algae. relationships. Outbreaks of P. fewer than 15 acres. Enough potatoes could be structure of these four countries as well as that sporophyte (p. 532) ity by The Princeton Review. thallus (p. 530) infestans are minimized by the use grown on a few acres to support an entire family of Ireland. Green, red, and brown algae, often called sea- of fungicides, but new resistant for a year. By 1845, the potato crop fed a large Most of the Irish quickly adapted to their weeds, have complex life cycles that alternate between haploid and diploid generations. strains have arisen that are diffi- percentage of the Irish population. new homes. For example, in the United States, UUNDERSTANDINGNDERSTANDING MMAINAIN IIDEASDEAS cult to control and that destroy some Irish became politically active. In fact, Invasion of a downy mildew many crops. In addition, the Historians John F. Kennedy, who was president of the 1. a suggest that Phytophthora infestans arrived in United States from 1960–1963, was the great- Section 19.3 Main Ideas Vocabulary c overuse of pesticides has Ireland in 1845 on a ship that arrived from great-grandson of an Irish tenant farmer who 2. Slime molds, water molds, and downy mildews plasmodium (p. 534) increased the number of crop- North America. The wet conditions in Ireland immigrated to the United States in 1848. 3. d Slime Molds, are funguslike protists that decompose organic damaging insects, making some during July and August that year were ideally Many Irish people who immigrated to the 4. a material to obtain nutrients. crops more susceptible to insect suited for the spread of the protist, a downy United States at the time of this famine settled Water Molds, destruction. mildew, which is classified in the phylum in the large East Coast cities, such as New York, and Downy Plasmodial and cellular slime molds change Philadelphia, and Boston. Their descendants are Mildews in appearance and behavior before producing now an integral part of American society and live reproductive structures. throughout the United States.

CONNECTION TO BIOLOGYIOLOGY 3. Which of the following pairs contains terms Today, fungicides, chemicals that prevent fungal NDERSTANDINGNDERSTANDING AINAIN DEASDEAS UU MM II most related to each other? growth, control outbreaks of Phytophthora infes- a. paramecium—alternation of generations tans. How might this information affect research 1. Which organisms cause red tides? b. asexual reproduction—gametophyte about the evolutionary relationships of fungus- a. dinoflagellates c. green algae like protists? c. sporozoan—cilia b. euglenoids d. red algae d. amoeba—pseudopodia To find out more about the Irish 2. Which organelle in protists is able to elimi- 4. Producers in aquatic food chains include potato famine and Phytophthora, nate excess water? ______. visit the Glencoe Science Web Site. a. anal pore c. contractile vacuole a. algae c. slime molds www.glencoe.com/sec/science b. mouth d. gullet b. protozoans d. amoebas

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Internet Address Book Resource Manager Note Internet addresses that you find useful in the space VIDEOTAPE below for quick reference. Chapter Assessment, pp. 109-114 MindJogger Videoquizzes MindJogger Videoquizzes Chapter 19: Protists Computer Test Bank Have students work in groups as they play BDOL Interactive CD-ROM, Chapter the videoquiz game to review key chapter 19 quiz concepts.

540 541 Chapter 19 Assessment Chapter 19 Assessment Chapter 19 Assessment Chapter 19 Assessment

5. a 24. Up to the late 1800s, malaria was common in 5. 12. AASSESSINGSSESSING KKNOWLEDGENOWLEDGE && SSKILLSKILLS 6. d Protists are classified on the basis of their The protozoan that causes malaria is classi- the extreme southeastern part of the United 24. Mosquitoes breed in water. ______. fied as a ______because it is a spore- States. In an attempt to fight the disease, 7. b During a summer ecology class, a group of The elimination of breeding a. nutrition producing parasite. ponds and wetlands were often filled in or 8. b high school students studied unicellular grounds reduces the mosquito b. method of locomotion 13. Volvox is an alga that lives in a ______, a drained. How do you suppose this action 9. a algae at a site in the middle of a pond. For population and reduces the risk c. reproductive abilities group of cells in close association. helped cut down on the number of malaria 10. c d. size three days and nights, they measured the of contracting malaria. 14. What type of cases? 11. eukaryotes 6. Euglenoids are unique algae because of their number of cells in the water at various structure does depths. They produced the following graph 12. sporozoan ______. the protist shown HINKING RITICALLY based on their data. HINKING RITICALLY 13. colony a. flagella to the right use TTHINKING CCRITICALLY TTHINKING CCRITICALLY 14. flagellum b. cilia to move? 25. Observing and Inferring Why do you sup- Locations of Diatoms c. silica walls 15. fragmentation pose many people who own aquariums add 25. Snails help keep the growth of d. heterotrophic nature 16. algae snails to them? Surface unwanted algae in check. 17. gametophyte; sporophyte 7. Which of the following is not a protist? 26. The nitrogen fertilizers run off 15. Asexual reproduction may occur when an 26. Formulating Hypotheses In agricultural 18. protozoans into water sources, where they organism breaks into pieces in a process regions where farmers use large amounts of 19. plasmodium stimulate the growth and known as ______. nitrogen fertilizers in their fields, local ponds 50 cm 20. cilia; flagellum a. c. and lakes often develop a thick, green scum reproduction of algae.

16. Diatoms and dinoflagellates are two phyla of of diatoms 27. A diatom reproduces asexually protists in the group collectively called containing algae in late summer. Hypothesize b. d. ______. why this happens. for several generations, with its APPLYINGPPLYING MAINAIN IDEASDEAS 27. Sequencing Sequence the stages of both 100 cm cell walls getting progressively A M I 17. The haploid form of an alga that has alterna- Location of highest concentration sexual and asexual reproduction in diatoms. 12 a.m. 12 p.m. 12 a.m. 12 p.m. 12 a.m. smaller and smaller. Eventually, 8. The algae that can survive in the deepest tion of generations is known as the ______, Times in hours 21. Finding a suitable host; produc- water are the ______? and the diploid form is the ______. 28. Concept Mapping Complete the concept the cell undergoes meiosis and map by using the following vocabulary terms: releases gametes that grow a ing many spores will improve a. brown algae c. diatoms 18. Amoebas, cilliates, flagellates, and sporozoans Interpreting Data Use the graph to answer amoebas, sporozoans, flagellates, protozoans, the possibility of survival b. red algae d. green algae are collectively called ______. the following questions. new cell with a large cell wall. because some of the spores may ciliates Then, the new diatoms begin 9. The largest and most complex of brown algae 19. Individual cells of a cellular slime mold may 1. At what time were the highest concen- find a host. are the ______. fuse to form a structure that resembles a Animal-like protists trations of diatoms at the surface? reproducing asexually. are called 22. oak forest—dry conditions stim- a. kelp c. sea lettuce ______and that reproduces. a. midnight c. 3 a.m. 28. 1. Protozoans; 2. Amoebas; 3. b. d. Ciliates; 4. Flagellates; 5. ulate spore-producing struc- Chlamydomonas Spirogyra 20. Paramecia move about using short projec- 1. b. noon d. 6 p.m. tures. 10. Which of the following are protected by ar- tions called ______, but euglenas move 2. At what time were the highest concen- Sporozoans 23. Answers will vary, but may mored plates? using a long projection, the ______. include include include include trations of diatoms about a meter below include cilia, pseudopodia, fla- a. kelp c. dinoflagellates the surface? gella, eyespots, contractile vac- b. fire algae d. diatoms 2. 3. 4. 5. a. midnight c. 3 a.m. AAPPLYINGPPLYING MMAINAIN IIDEASDEAS uoles, or others. 11. Unlike bacteria, all protists are ______. that use that use that use that produce b. noon d. 6 p.m. 21. Why is it a disadvantage for a sporozoan to pseudopods cilia to flagella to spores and 3. Which of the following is the best de- to move move move are parasites 1. b be a parasite? How might a sporozoan’s scription of the movement of diatoms in 2. a method of asexual reproduction offset this the water column? 3. c disadvantage? TTESTEST––TTAKINGAKING TTIPIP a. 6-hour cycle 4. They are photosynthetic b. 12-hour cycle 22. In which ecosystem would a plasmodial slime and move to the surface Work Weak Areas, Maintain Strong Ones mold transform itself into spore-producing CD-ROM c. 24-hour cycle It’s sometimes difficult to focus on all the concepts d. irregular cycling to utilize sunlight during structures more frequently: a rainy forest in For additional review, use the assessment needed for a test. So ask yourself “What’s my daylight hours. the Pacific Northwest or a dry, oak forest in options for this chapter found on the Biology: The 4. Interpreting Data Why might the dia- strongest area?” and “What’s my weakest area?” the Midwest? Explain your answer. Dynamics of Life Interactive CD-ROM and on the toms show the pattern found by the Focus most of your energy on your weak areas. But Glencoe Science Web Site. also put in some “upkeep” time in your strongest 23. Give three examples of organelles that help group of high school students? www.glencoe.com/sec/science areas. protists maintain homeostasis in their envi- ronments.

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