Ch21 PPT MADER Biology 2024 Release PDF

Because learning changes everything. ® Biology Sylvia S. Mader...

Because learning changes everything. ® Biology Sylvia S. Mader Michael Windelspecht Chapter 21 Protist Evolution and Diversity Access the text alternative for slide images. © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  Chapter Outline 21.1 Overview of Protists 21.2 Supergroup Excavata 21.3 Supergroup Chromalveolata 21.4 Supergroup Rhizaria 21.5 Supergroup Archaeplastida 21.6 Supergroup Amoebozoa 21.7 Supergroup Opisthokonta © McGraw Hill LLC 2  Learning Objectives 21.1 Overview of Protists 21.5 Supergroup Archaeplastida Explain the origin of eukaryotic organelles. Identify the distinguishing characteristics of Assign protists into one of two groups based Archaeplastida. on mode of nutrition. Describe the life cycles of Archaeplastida. Understand that protists represent multiple 21.6 Supergroup Amoebozoa evolutionary lineages. Describe the distinguishing features of 21.2 Supergroup Excavata amoebozoans. Describe the distinguishing characteristics of Describe the life cycle of a plasmodial slime excavates. mold. Identify pathogenic excavate species. 21.7 Supergroup Opisthokonta 21.3 Supergroup Chromalveolata List major groups of organisms found in the Identify the characteristics of the supergroup Opisthokonta. Chromalveolata supergroup. Describe the structure of choanoflagellates. Identify unique species of the Chromalveolata supergroup. Describe the life cycle of Plasmodium. 21.4 Supergroup Rhizaria Identify characteristics of the supergroup Rhizaria. Identify unique species of the supergroup Rhizaria. Describe endosymbiosis in the Cercozoa. © McGraw Hill LLC 3  21.1 Overview of Protists Historically classified in the domain Eukarya and the kingdom Protista; however, with the evolution of eukaryotes, protists are found in all of the supergroups. Endosymbiotic hypothesis Aerobic bacteria became mitochondria. Cyanobacteria became chloroplasts. Vary in size from microscopic algae and protozoans to kelp more than 200 m in length. Although many protists are unicellular, they are highly complex. Some protists are colonial or filamentous. © McGraw Hill LLC 4  Nutrition of Protists Algae are photosynthetic. Protozoans are heterotrophic. Some ingest food by endocytosis. Some protozoans are mixotrophic. Mixotrophs combine autotrophic and heterotrophic nutritional modes. © McGraw Hill LLC 5  Life Cycle of Protists Asexual reproduction is most common. Sexual reproduction may occur when environmental conditions are unfavorable. Formation of dormant cells known as spores and cysts allows protists to survive hostile environments. In parasites, a cyst may serve as a means of transfer to a new host. © McGraw Hill LLC 6  Biology of Protists Protists are of enormous ecological importance. Photoautotrophs: Produce oxygen. Form the foundation of the food chain in both freshwater and saltwater ecosystems. Are a major component of plankton Organisms that are suspended in the water. Serve as food for heterotrophic protists and animals. Whales, the largest organism in the sea, feed on plankton, some of the smallest organisms in the sea. © McGraw Hill LLC 7 Evolution and Diversity of Protists Complexity and diversity of protists make them difficult to classify. Protists are not monophyletic. They do not all belong to the same evolutionary lineage. Classified into six supergroups. Supergroup is a taxonomic group below domain and above kingdom. © McGraw Hill LLC 8  Supergroups Table 21.1 Eukaryotic Supergroups Table divided into two columns summarizes eukaryotic supergroups. The column headers are marked from left to right as: Supergroup and members. © McGraw Hill LLC 9  Figure 21.1 Proposed Evolutionary Relationships Among the Eukaryotic Supergroups Access the text alternative for slide imag es. © McGraw Hill LLC 10  21.2 Supergroup Excavata Excavates Atypical or absent mitochondria Distinctive flagella and/or deep (excavated) oral grooves Excavates include: Diplomonads Parabasalids Euglenozoans © McGraw Hill LLC 11  SG Excavata: Diplomonads and Parabasalids Unicellular and flagellated Endosymbionts of animals Survive in anaerobic (low-oxygen) environments Lack mitochondria Rely on fermentation for ATP production Two nuclei and two sets of flagella © McGraw Hill LLC 12  SG Excavata: Diplomonads and Parabasalids Diplomonads Cell has two nuclei and two sets of flagella. Well-known for causing various diseases in humans Giardia lamblia causes severe diarrhea. Cysts are transmitted in contaminated water. Beavers are important reservoir hosts. Parabasalids Unique fibrous connection between the Golgi apparatus and flagella. Trichomonas vaginalis causes trichomoniasis, a sexually transmitted disease that usually only causes symptoms in females. © McGraw Hill LLC 13  SG Excavata: Diplomonads - Giardia lamblia Figure 21.2 Cultura Creative/Alamy Stock Photo © McGraw Hill LLC 14  SG Excavata: Parabasilids - Trichomonas vaginalis Figure 21.3 Kateryna Kon/Shutterstock © McGraw Hill LLC 15  SG Excavata: Euglenozoans Small freshwater unicellular organisms Possess mitochondria Lack a cell wall and instead have protein covering surrounding the cell Includes: Free-living euglenids Parasitic kinetoplastids © McGraw Hill LLC 16  SG Excavata: Euglenozoans – Euglenids Asexual, single-celled freshwater protists Some are mixotrophs, some are photoautotrophs, and some are heterotrophs. Have two flagella and an eyespot that detects light One flagellum is much longer than the other. Longer flagella is called a tinsel flagellum because of hair-like projections. Cell is bounded by a flexible pellicle. Contractile vacuole rids the body of excess water. Chloroplasts, if present: Surrounded by three, rather than two, membranes. Special region of the chloroplast, the pyrenoid, produces an unusual type of carbohydrate called paramylon. © McGraw Hill LLC 17  Euglenids - Euglena Figure 21.4 Access the text alternative for slide imag es. © McGraw Hill LLC (b): Lebendkulturen.de/Shutterstock 18  The brain-eating amoeba Is it real? It is. But the name is misleading. It is not classified with the actual amoebas in Supergroup Amoebozoa, but here in Supergroup Excavata. Naegleria fowleri is known as the “brain-eating amoeba.” Can cause a fatal brain infection Lives in warm fresh water and can be acquired by inhaling water when swimming © McGraw Hill LLC 19  SG Excavata: Euglenozoans – Kinetoplastids Unicellular, flagellated protozoans. Named for distinctive kinetoplast (large mass of DNA located in mitochondria). Trypanosomes are parasitic kinetoplastids. Trypanosoma brucei causes African sleeping sickness. Transmitted by the tsetse fly Causes lethargy due to inadequate supply of oxygen to the brain Trypanosoma cruzi causes Chagas disease. © McGraw Hill LLC 20 Kinetoplastids: Trypanosoma brucei Figure 21.5 Access the text alternative for slide imag es. © McGraw Hill LLC (a): Eye of Science/Science Source 21  Transmission Pattern of Trypanosoma brucei Figure 21A Access the text alternative for slide images. (children): Zoonar GmbH/Alamy Stock Photo; (tsetse fly): Nigel Cattlin/Alamy Stock Photo; (goat): Eureka/Alamy Stock Photo; (pig): Anatolii © McGraw Hill LLC 22  21.3 Supergroup Chromalveolata Chromalveolata includes two large subgroups – Alveolates and Stramenopiles Alveolates: All unicellular Have small air sacs (alveoli) beneath the plasma membrane May support cell surface or aid in membrane transport Includes: Dinoflagellates Apicomplexans Ciliates © McGraw Hill LLC 23  SG Chromalveolata: Alveolates – Dinoflagellates Around 1,500 identified species of dinoflagellates. Single cell is usually bounded by protective cellulose plates impregnated with silicates. Typically have two flagella. One flagellum acts as a rudder. The other causes the cell to spin as it moves forward. © McGraw Hill LLC 24  Dinoflagellate Structure Figure 21.6 Biophoto Associates/Science Source © McGraw Hill LLC 25  SG Chromalveolata: Alveolates – Dinoflagellates Endosymbiotic dinoflagellates called zooxanthellae are found in corals. Dinoflagellates provide their host with organic nutrients. Corals provide shelter, nutrients, and protection. Alexandrium catanella can cause red tide. Produce a powerful neurotoxin that causes massive fish kills. Consuming shellfish during an outbreak can cause respiratory paralysis in humans. © McGraw Hill LLC 26 Dinoflagellate Bloom and Fish Kill Figure 21.7 Access the text alternative for slide images. © McGraw Hill LLC (a): Julian Nieman/Alamy Stock Photo; (b): Todd Yates/Corpus Christi Caller-Times/AP Images 27  SG Chromalveolata: Alveolates – Apicomplexans Nonmotile, spore-forming, parasites of animals Also known as “sporozoans” Unique organelle called apicoplast used to penetrate host cell Most serious parasitic disease of humans is malaria. Plasmodium spp Affects 240 million people each year, of whom more than 600,000 die of the infection Transmitted by female Anopheles mosquito, infects blood cells Most common in densely populated, tropical areas of the globe © McGraw Hill LLC 28  Life Cycle of Plasmodium vivax Figure 21.8 Access the text alternative for slide images. © McGraw Hill LLC 29  SG Chromalveolata: Alveolates – Ciliates Ciliates are among the most complex of the protozoans. Single cells bound by a pellicle Hundreds of cilia beat in a coordinated rhythm. Heterotrophic – most ciliates ingest their food via an oral groove and gullet. Most free-living, some parasitic They possess two types of nuclei: Macronucleus—controls normal cell metabolism Micronuclei—participate in reproduction © McGraw Hill LLC 30  Ciliate Structure Figure 21.9 Access the text alternative for slide images. © McGraw Hill LLC (photos): (a): micro_photo/iStock/Getty Images; (b): Ed Reschke/Stone/Getty Images; (c): Eric Grave/Science Source 31  SG Chromalveolata: Alveolates – Ciliates Reproduction: They divide by transverse binary fission during asexual reproduction. Sexual reproduction involves conjugation and exchange of haploid micronuclei. Examples: Paramecium Stentor Vorticella Ichthyophthirius is an ectoparasitic protozoan that causes the fish disease “ick.” © McGraw Hill LLC 32  Ciliates Examples Figure 21.9 Access the text alternative for slide images. © McGraw Hill LLC (photos): (a): micro_photo/iStock/Getty Images; (b): Ed Reschke/Stone/Getty Images; (c): Eric Grave/Science Source 33  SG Chromalveolata: Stramenopiles Stramenopiles: Unicellular, colonial, and multicellular forms Have a “hairy” flagellum (flagellum with accessory tubular hairs) Includes: Diatoms Golden brown algae Brown algae Oomycetes © McGraw Hill LLC 34  SG Chromalveolata: Stramenopiles – Diatoms Single cells with ornate silica shells made of two halves. Photoautotrophs that use the carotenoid pigment fucoxanthin, in addition to chlorophylls a and c Make up a significant portion of the phytoplankton. Reproduce asexually and sexually. Diatomaceous earth, made of the remains of diatoms’ silica shell, is used as: A filtering agent Soundproofing material A polishing abrasive Nontoxic insecticide © McGraw Hill LLC 35  Diatoms Example Figure 21.10 Dennis Kunkel Microscopy/Science Source © McGraw Hill LLC 36  SG Chromalveolata: Stramenopiles – Golden Brown Algae Unicellular or colonial. Photoautotrophs that use yellow-brown carotenoid accessory pigments, in addition to chlorophylls a and c Contribute to freshwater and marine phytoplankton. Many species are mixotrophs that are capable of photosynthesis and phagocytosis May or may not have a silica shell Usually have two flagella with tubular hairs. © McGraw Hill LLC 37 Ochromonas, a Golden Brown Alga Figure 21.11 © McGraw Hill LLC 38  SG Chromalveolata: Stramenopiles – Brown Algae Filamentous, colonial, and multicellular Range in size from microscopic singular filaments to 100 meter- long multicellular kelp Photoautotrophs that use the carotenoid pigment xanthophyll, in addition to chlorophylls a and c provides brown color. Most live in colder ocean waters along rocky coasts (e.g. kelp forests). Holdfast anchors them to rocks Excess food is stored as a carbohydrate called laminarin. Harvested for food and fertilizer. © McGraw Hill LLC 39  SG Chromalveolata: Stramenopiles – Brown Algae Examples: Laminaria (kelp) and Fucus (rockweed) are common intertidal shoreline seaweeds. Laminaria shows tissue differentiation. Transports organic nutrients in a tissue resembling phloem in land plants. Some Fucus spp have an exclusively sexual lifecycle (vs alternation of generations) Macrocystis and Nereocystis are large seaweeds that form kelp forests Macrocystis is the source of algin, a thickener for foods such as ice cream, sherbet, and cream cheese. © McGraw Hill LLC 40  Brown Algae Examples Figure 21.12 Access the text alternative for slide images. © McGraw Hill LLC 41  SG Chromalveolata: Stramenopiles – Oomycetes Fungus-like diploid protists (aka “water molds”) Form furry growths on their food source. Most live in water and are saprotrophic, feeding on dead organic matter Some live on land and parasitize insects and plants. Responsible for the potato famine in Ireland in the 1840s and the mildew of grapes in France in the 1870s. Life cycle similar to Fungi Cell walls composed largely of cellulose (vs chitin in true Fungi) © McGraw Hill LLC 42 Oomycete (Water Mold) Example Figure 21.13 Noble Proctor/Science Source © McGraw Hill LLC 43  21.4 Supergroup Rhizaria Classified together based on rRNA sequence data. Members of this group do not share very many morphological characteristics. All unicellular Most have thin, threadlike pseudopods Many produce a shell that can be fossilized Includes: cercozoans foraminiferans radiolarians © McGraw Hill LLC 44  SG Rhizaria: Cercozoa Have pseudopods or flagella. Many have an outer netlike appearance. Some species have endosymbiotic cyanobacteria. Endosymbiosis event occurred recently (~100 MYA vs ~1 BYA for true chloroplasts) © McGraw Hill LLC 45  Cercozoan Pulinella chromatophora Figure 21.14 Dr. Oliver Skibbe/Science Source © McGraw Hill LLC 46  SG Rhizaria: Foraminiferans and Radiolarians Heterotrophs with fine, threadlike pseudopods and a skeleton/shell known as a test. Foraminiferans (forams) – multichambered chalky calcium carbonate test lies exterior to plasma membrane Pseudopods are internal to, and extend through pores in, test. Radiolarians – radially-arranged spines project from glassy silicon test that lies interior to plasma membrane Pseudopods are external to test © McGraw Hill LLC 47  SG Rhizaria: Foraminiferans and Radiolarians Tests of dead foraminiferans and radiolarians fossilize well Fossils date back to the Precambrian. Each geological period has a distinctive type of foraminiferan that can be used as index fossils Ancient foram deposits formed the White Cliffs of Dover. Foram fossils are in Egyptian Pyramids limestone Fossils are used as an indicator of oil deposits on land and sea. © McGraw Hill LLC 48  Foraminiferan and Radiolarian Examples Figure 21.15 Access the text alternative for slide images. © McGraw Hill LLC (a): (cliffs): Platslee/Shutterstock; (inset): NHPA/Photoshot/SuperStock; (b): Eye of Science/Science Source 49  21.5 Supergroup Archaeplastida Photoautotrophs that have plastids derived from endosymbiotic cyanobacteria. Chloroplasts have two membranes Other characteristics: Cell walls contain cellulose Store extra energy as starch Includes: red algae green algae land plants © McGraw Hill LLC 50  SG Archaeplastida: Red Algae Multicellular marine seaweeds. Feathery or flat, ribbon-like branched morphologies Much smaller and more delicate than brown algae. Possess red and blue accessory pigments (phycobilins) absorb wavelengths that penetrate deeper into water so able to live deeper than green algae Live mostly in warmer tropical seawater, some at depths greater than 70m. Coralline red algae have calcium carbonate in their cell walls and contribute to coral reefs © McGraw Hill LLC 51  Red Algae Figure 21.16 Shutterstock/Antonio Martin © McGraw Hill LLC 52  SG Archaeplastida: Red Algae Economic Importance Agar – capsules for drugs, dental impressions, cosmetics, bacterial culture medium, electrophoresis, food prep. Carrageenan – an emulsifying agent used in the production of chocolate and cosmetics. Nori – The reddish-black wrappings around sushi rolls consist of processed Porphyra blades. © McGraw Hill LLC 53  Red Algae Products Figure 21C,D,E © McGraw Hill LLC 54  SG Archaeplastida: Green Algae Use both chlorophylls a and b for photosynthesis They may be orange-, red-, or rust-colored. Inhabit a variety of environments including oceans, freshwater, snowbanks, tree bark, and the backs of turtles. Many are symbionts with fungi, plants, or animals. Morphology varies from unicellular, to filamentous or colonial, to multicellular Seaweeds are multicellular and resemble leaves of lettuce. Subdivided into two groups: Chlorophytes Charophytes Land plants are thought to be derived from charophytes. © McGraw Hill LLC 55  SG Archaeplastida: Green Algae – Chlorophytes Chlamydomonas unicellular chlorophyte that inhabits still, freshwater pools Fossil ancestors date back over a billion years. Structure: Defined cell wall Two flagella single, large, cup-shaped chloroplast. Chloroplast contains a pyrenoid where starch is synthesized. Many spp have a bright red, light-sensitive eyespot. Guides organism toward light for photosynthesis. © McGraw Hill LLC 56  Electron Micrograph of Chlamydomonas Figure 21.17 Access the text alternative for slide images. © McGraw Hill LLC Biophoto Associates/Science Source 57  SG Archaeplastida: Green Algae – Chlorophytes Chlamydomonas Reproduction: In favorable conditions, Chlamydomonas exists as haploid cells which reproduce asexually by mitosis. In unfavorable conditions, Chlamydomonas reproduces sexually. Produce diploid zygospores which lay dormant until conditions are favorable. Zygospores undergo meiosis producing zoospores which grow to become vegetative cells. © McGraw Hill LLC 58  Haploid-dominant Life Cycle of Chlamydomonas Figure 21.18 Access the text alternative for slide images. © McGraw Hill LLC 59  SG Archaeplastida: Green Algae – Chlorophytes Volvox Colonial green alga that forms a hollow sphere with 1000s of cells arranged in a single layer surrounding a watery interior A colony is a loose association of independent cells. Volvox colonies moves because flagella beat in a coordinated fashion. Some cells are specialized for reproduction. Each can divide asexually to form a new daughter colony within the parental colony. The daughter colony leaves the parental colony by releasing an enzyme that dissolves away a portion of the parental colony. © McGraw Hill LLC 60  Volvox Example Figure 21.19 Access the text alternative for slide images. © McGraw Hill LLC (both): Manfred Kage/Science Source 61  SG Archaeplastida: Green Algae – Chlorophytes Ulva Multicellular green alga with blade-like structure Commonly called “sea lettuce” Body is two cells thick and can be as much as a meter long. Sexual cycle involves the alternation of generations, similar to land plants © McGraw Hill LLC 62  Ulva Example Figure 21.20 Access the text alternative for slide imag es. © McGraw Hill LLC (a): ©Evelyn Jo Johnson 63  SG Archaeplastida: Green Algae – Charophytes Filamentous (chains of cells end-to-end) green algae. Spirogyra Found in green masses on the surfaces of ponds and streams Unbranched with ribbon-like, spiraled chloroplasts Sexual reproduction by conjugation A temporary union during which the cells exchange genetic material. Two haploid filaments line up parallel to each other. Cell contents of one filament move into the cells of the other filament forming diploid zygospores. Zygospores eventually undergo meiosis to produce new haploid filaments. © McGraw Hill LLC 64  Spirogyra Figure 21.21 Access the text alternative for slide images. © McGraw Hill LLC (b): M.I. Walker/Science Source 65  SG Archaeplastida: Green Algae – Chlorophytes Chara found in freshwater lakes and ponds. Structure: Encrusted with calcium carbonate deposits. Commonly called a “stonewort” Main strand of alga can be over a meter long. Cells anchored by rhizoids. Whorls of branches occur at multicellular nodes. DNA sequencing data suggest the stoneworts are most closely related to land plants. © McGraw Hill LLC 66  Chara Examples Figure 21.22 (a): Bob Gibbons/Alamy Stock Photo; (b): ©Kingsley Stern © McGraw Hill LLC 67  21.6 Supergroup Amoebozoa Protozoans that move by pseudopods (formed when cytoplasm streams forward in a particular direction) Amoeboids protists that move and ingest their food with pseudopods. Feed by phagocytosis. Examples: Amoeba proteus is commonly studied in biology labs. Entamoeba histolytica is a parasite of the human colon that causes amoebic dysentery © McGraw Hill LLC 68  Amoeba proteus Figure 21.23 Access the text alternative for slide images. © McGraw Hill LLC 69  21.6 Supergroup Amoebozoa Slime Molds Important decomposers on dead plant material Once classified as fungi but lack cell walls Vegetative state is mobile and amoeboid. Produce spores by meiosis Spores germinate to form gametes. Two forms of slime molds Plasmodial slime molds Cellular slime molds © McGraw Hill LLC 70  SG Amoebozoa: Plasmodial Slime Molds Body in the form of a “plasmodium” – diploid, multinucleated, sluglike cytoplasmic mass surrounded by a slimy sheath. Different from the Alveolate Plasmodium genus Consumes decaying plant material as it creeps along ground. © McGraw Hill LLC 71  SG Amoebozoa: Plasmodial Slime Molds Reproduction similar to fungi: In unfavorable conditions, produces many sporangia, reproductive structures that produce spores. Aggregate of sporangia is called a fruiting body. Spores can remain dormant until environmental conditions are suitable. Spores germinate to form either a haploid flagellated cell or an amoeboid cell. Two haploid cells fuse to form a zygote that grows into a multinucleated plasmodium. © McGraw Hill LLC 72  Life Cycle of a Slime Mold Figure 21.24 Access the text alternative for slide images. © McGraw Hill LLC (photos): (left): NHPA/Photoshot/SuperStock; (right): Nature Picture Library/SuperStock 73  SG Amoebozoa: Cellular Slime Molds Exist as individual amoeboid cells. Common in soil and feed on bacteria and yeasts. Cells release a chemical when environmental conditions are unfavorable. Cells then aggregate and form a pseudoplasmodium. Forms sporangia and spores. When environmental conditions improve, spores germinate releasing amoeboid cells. © McGraw Hill LLC 74 21.7 Supergroup Opisthokonta Includes animals, fungi, and several closely related protists. Choanoflagellates Some single-celled and some colonial. Filter feeders with cells that resemble the choanocytes found inside sponges. Each cell has a posterior flagella surrounded by a collar. As flagella move, water is drawn through cell and food captured by phagocytosis. © McGraw Hill LLC 75  Colonial Choanoflagellates Figure 21.25 Access the text alternative for slide images. © McGraw Hill LLC 76  End of Main Content Because learning changes everything. ® www.mheducation.com © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.