Plants, Fungi, and the Move onto Land Chapter 16 Plants, Fungi, and the Move onto Land

Bacteria Archaea Protists Eukarya Plants Fungi Animals Figure 16.UN01 Figure 16.UN01 Plant tree orientation diagram Fungi Animals Figure 16.UN01

COLONIZING LAND Plants are terrestrial organisms that include forms that have returned to water, such as water lilies. Student Misconceptions and Concerns 1. Students often misunderstand evolution as a deliberate and directed process. This chapter provides good examples of how evolution actually occurs. The American chestnut trees were driven nearly to extinction because they did not possess the adaptations that would have helped them to survive the blight fungus. If evolution involved acquiring needed adaptations, why then would the chestnuts suffer? As plants evolved onto land, the properties of a terrestrial environment selected amongst the diversity of the species that existed. For example, plants that produced leaves with more wax had the advantage of greater water retention. Plants did not evolve adaptations to address the needs of living on land. Instead, terrestrial adaptations evolved in plants that already had the traits that permitted them to invade this new environment. 2. The text discusses charophytes as the group most closely related to plants. Students might misinterpret this to mean that modern charophyceans were the direct ancestors of plants. Instead, modern charophyceans and plants share a common ancestor, but each has been evolving since the lineages diverged. This same confusion occurs when considering the evolutionary history of humans and chimps. Humans and chimps share a common ancestor. Modern humans did not evolve from modern chimps. Teaching Tips 1. Consider challenging your students to suggest the new demands of living on land. They could work in small groups in class or outside of class and e-mail their responses to you. By asking them to consider the challenges that plants (and in the next chapter, animals) face when they moved onto land prepares them for the discussions of the adaptations that resulted and are discussed in Chapter 16. 2. The authors make a connection between water lilies and whales, because both are aquatic organisms that evolved from terrestrial forms. 3. Point out to your students that in an aquatic environment resources (such as nutrients and water) are exposed to nearly the entire plant. However, on land, structural specializations have evolved because resources are no longer evenly exposed to the plant (roots are subterranean adaptations and shoots are aerial adaptations). 4. Consider the analogy between vascular systems in plants and a major interstate highway, with traffic running in opposite directions. 5. Have your students discuss the specific advantages of similar adaptations in the reproductive systems of plants and mammals. What are the advantages to keeping the developing embryos with the parent? (For example: The embryonic environment can be carefully regulated by the parent and the parent can better protect the young from damage, disease, or predation.)

Terrestrial Adaptations of Plants Structural Adaptations A plant is A multicellular eukaryote A photoautotroph, making organic molecules by photosynthesis Student Misconceptions and Concerns 1. Students often misunderstand evolution as a deliberate and directed process. This chapter provides good examples of how evolution actually occurs. The American chestnut trees were driven nearly to extinction because they did not possess the adaptations that would have helped them to survive the blight fungus. If evolution involved acquiring needed adaptations, why then would the chestnuts suffer? As plants evolved onto land, the properties of a terrestrial environment selected amongst the diversity of the species that existed. For example, plants that produced leaves with more wax had the advantage of greater water retention. Plants did not evolve adaptations to address the needs of living on land. Instead, terrestrial adaptations evolved in plants that already had the traits that permitted them to invade this new environment. 2. The text discusses charophytes as the group most closely related to plants. Students might misinterpret this to mean that modern charophyceans were the direct ancestors of plants. Instead, modern charophyceans and plants share a common ancestor, but each has been evolving since the lineages diverged. This same confusion occurs when considering the evolutionary history of humans and chimps. Humans and chimps share a common ancestor. Modern humans did not evolve from modern chimps. Teaching Tips 1. Consider challenging your students to suggest the new demands of living on land. They could work in small groups in class or outside of class and e-mail their responses to you. By asking them to consider the challenges that plants (and in the next chapter, animals) face when they moved onto land prepares them for the discussions of the adaptations that resulted and are discussed in Chapter 16. 2. The authors make a connection between water lilies and whales, because both are aquatic organisms that evolved from terrestrial forms. 3. Point out to your students that in an aquatic environment resources (such as nutrients and water) are exposed to nearly the entire plant. However, on land, structural specializations have evolved because resources are no longer evenly exposed to the plant (roots are subterranean adaptations and shoots are aerial adaptations). 4. Consider the analogy between vascular systems in plants and a major interstate highway, with traffic running in opposite directions. 5. Have your students discuss the specific advantages of similar adaptations in the reproductive systems of plants and mammals. What are the advantages to keeping the developing embryos with the parent? (For example: The embryonic environment can be carefully regulated by the parent and the parent can better protect the young from damage, disease, or predation.) © 2010 Pearson Education, Inc.

In terrestrial habitats, the resources that a photosynthetic organism needs are found in two very different places: Light and carbon dioxide are mainly available in the air Water and mineral nutrients are found mainly in the soil Student Misconceptions and Concerns 1. Students often misunderstand evolution as a deliberate and directed process. This chapter provides good examples of how evolution actually occurs. The American chestnut trees were driven nearly to extinction because they did not possess the adaptations that would have helped them to survive the blight fungus. If evolution involved acquiring needed adaptations, why then would the chestnuts suffer? As plants evolved onto land, the properties of a terrestrial environment selected amongst the diversity of the species that existed. For example, plants that produced leaves with more wax had the advantage of greater water retention. Plants did not evolve adaptations to address the needs of living on land. Instead, terrestrial adaptations evolved in plants that already had the traits that permitted them to invade this new environment. 2. The text discusses charophytes as the group most closely related to plants. Students might misinterpret this to mean that modern charophyceans were the direct ancestors of plants. Instead, modern charophyceans and plants share a common ancestor, but each has been evolving since the lineages diverged. This same confusion occurs when considering the evolutionary history of humans and chimps. Humans and chimps share a common ancestor. Modern humans did not evolve from modern chimps. Teaching Tips 1. Consider challenging your students to suggest the new demands of living on land. They could work in small groups in class or outside of class and e-mail their responses to you. By asking them to consider the challenges that plants (and in the next chapter, animals) face when they moved onto land prepares them for the discussions of the adaptations that resulted and are discussed in Chapter 16. 2. The authors make a connection between water lilies and whales, because both are aquatic organisms that evolved from terrestrial forms. 3. Point out to your students that in an aquatic environment resources (such as nutrients and water) are exposed to nearly the entire plant. However, on land, structural specializations have evolved because resources are no longer evenly exposed to the plant (roots are subterranean adaptations and shoots are aerial adaptations). 4. Consider the analogy between vascular systems in plants and a major interstate highway, with traffic running in opposite directions. 5. Have your students discuss the specific advantages of similar adaptations in the reproductive systems of plants and mammals. What are the advantages to keeping the developing embryos with the parent? (For example: The embryonic environment can be carefully regulated by the parent and the parent can better protect the young from damage, disease, or predation.)

Plant Alga Reproductive structures (such as those in flowers) contain spores and gametes Plant Leaf performs photosynthesis Cuticle reduces water loss; stomata regulate gas exchange Shoot supports plant (and may perform photosynthesis) Alga Whole alga performs photosynthesis; absorbs water, CO2, and minerals from the water Figure 16.1 Structural adaptations of algae and plants Surrounding water supports the alga Roots anchor plant; absorb water and minerals from the soil (aided by fungi) Figure 16.1

Xylem transports water and minerals from roots to leaves Phloem Vascular tissue Xylem Figure 16.3 Network of vascular tissue in a leaf. Phloem distributes sugars from leaves to the roots and other nonphotosynthetic parts of the plant Oak leaf Figure 16.3

The fossil record chronicles four major periods of plant evolution. Charophytes (a group of green algae) Origin of first terrestrial adaptations (about 475 mya) Ancestral green algae Nonvascular plants (bryophytes) Bryophytes Land plants Origin of vascular tissue (about 425 mya) Ferns and other seedless vascular plants Seedless vascular plants Origin of seeds (about 360 mya) Vascular plants Gymnosperms Origin of flowers (about 140 mya) Angiosperms Seed plants Figure 16.6 Highlights of plant evolution 600 500 400 300 200 100 Millions of years ago The history of the plant kingdom is a story of adaptation to diverse terrestrial habitats. Figure 16.6

(1) About 475 million years ago plants originated from an algal ancestor giving rise to bryophytes, nonvascular plants, including mosses, liverworts, and hornworts that are nonvascular plants without Lignified walls True roots True leaves

(2) About 425 million years ago ferns evolved With vascular tissue hardened with lignin But without seeds

(3) About 360 million years ago gymnosperms evolved with seeds that consisted of an embryo packaged along with a store of food within a protective covering but not enclosed in any specialized chambers. Today, conifers, consisting mainly of cone-bearing trees such as pines, are the most diverse and widespread gymnosperms.

(4) About 140 million years ago angiosperms evolved with complex reproductive structures called flowers that bear seeds within protective chambers called ovaries. The great majority of living plants are angiosperms: They include fruit and vegetable crops, grains, grasses, and most trees They are represented by more than 250,000 species

(seedless vascular plants) PLANT DIVERSITY Bryophytes (nonvascular plants) Ferns (seedless vascular plants) Gymnosperms (naked-seed plants) Angiosperms (flowering plants) Figure 16.7 The major groups of plants Figure 16.7

Bryophytes Bryophytes, most commonly mosses Sprawl as low mats over acres of land Need water to reproduce because their sperm swim to reach eggs within the female gametangium Have two key terrestrial adaptations: A waxy cuticle that helps prevent dehydration The retention of developing embryos within the mother plant’s gametangium Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Figure 16.8 A peat moss bog in Scotland

Mosses have two distinct forms: The gametophyte, which produces gametes The sporophyte, which produces spores Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Spores Spore capsule Sporophyte Gametophytes Figure 16.9 Figure 16.9 The two forms of a moss Gametophytes Figure 16.9

The life cycle of a moss exhibits an alternation of generations shifting between the gametophyte and sporophyte forms. Mosses and other bryophytes are unique in having the gametophyte as the larger, more obvious plant. Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Gametes: sperm and eggs (n) Gametophyte (n) Key osis Mit Gametes: sperm and eggs (n) Gametophyte (n) Figure 16.10 Alternation of generations (Step 1) Key Haploid (n) Diploid (2n) Figure 16.10-1

Gametes: sperm and eggs (n) Gametophyte (n) Zygote (2n) Key osis Mit Gametes: sperm and eggs (n) Gametophyte (n) FERTILIZATION Zygote (2n) Figure 16.10 Alternation of generations (Step 2) Key Haploid (n) Diploid (2n) Figure 16.10-2

Gametes: sperm and eggs (n) Gametophyte (n) Spore capsule Zygote osis Mit Gametes: sperm and eggs (n) Gametophyte (n) FERTILIZATION Spore capsule Zygote (2n) Sporophyte (2n) o Mi sis t Figure 16.10 Alternation of generations (Step 3) Key Haploid (n) Diploid (2n) Figure 16.10-3

Gametes: sperm and eggs (n) Spores (n) Gametophyte (n) Spore capsule osis Mit osis Mit Gametes: sperm and eggs (n) Spores (n) Gametophyte (n) MEIOSIS FERTILIZATION Spore capsule Zygote (2n) Sporophyte (2n) t o Mi sis Figure 16.10 Alternation of generations (Step 5) Key Haploid (n) Diploid (2n) Figure 16.10-5

Key Haploid (n) Diploid (2n) Figure 16.14 (a) Sporophyte dependent Gametophyte (n) Sporophyte (2n) Sporophyte (2n) Sporophyte (2n) Gametophyte (n) Gametophyte (n) (a) Sporophyte dependent on gametophyte (e.g., mosses) (b) Large sporophyte and small, Independent gametophyte (e.g., ferns) (c) Reduced gametophyte dependent on sporophyte (seed plants) Figure 16.14 Three variations on alternation of generations in plants. Key Haploid (n) Diploid (2n) Figure 16.14

Ferns Ferns are The sperm of ferns, like those of mosses Seedless vascular plants By far the most diverse with more than 12,000 known species The sperm of ferns, like those of mosses Have flagella Must swim through a film of water to fertilize eggs Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

As they died, these forests formed coal. During the Carboniferous period, from about 360 to 300 million years ago, ferns Were part of a great diversity of seedless plants Formed swampy forests over much of what is now Eurasia and North America As they died, these forests formed coal. Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Figure 16.12 A "coal forest" of the Carboniferous period

Key Haploid (n) Diploid (2n) Figure 16.14 (a) Sporophyte dependent Gametophyte (n) Sporophyte (2n) Sporophyte (2n) Sporophyte (2n) Gametophyte (n) Gametophyte (n) (a) Sporophyte dependent on gametophyte (e.g., mosses) (b) Large sporophyte and small, Independent gametophyte (e.g., ferns) (c) Reduced gametophyte dependent on sporophyte (seed plants) Figure 16.14 Three variations on alternation of generations in plants. Key Haploid (n) Diploid (2n) Figure 16.14

Gymnosperms At the end of the Carboniferous period, the climate turned drier and colder, favoring the evolution of gymnosperms, which can Complete their life cycles on dry land Withstand long, harsh winters The descendants of early gymnosperms include the conifers, or cone-bearing plants. Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Conifers Conifers Cover much of northern Eurasia and North America Are usually evergreens, which retain their leaves throughout the year Include the tallest, largest, and oldest organisms on Earth Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Terrestrial Adaptations of Seed Plants Conifers and most other gymnosperms have three additional terrestrial adaptations: Further reduction of the gametophyte Pollen Seeds Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Key Haploid (n) Diploid (2n) Figure 16.14 (a) Sporophyte dependent Gametophyte (n) Sporophyte (2n) Sporophyte (2n) Sporophyte (2n) Gametophyte (n) Gametophyte (n) (a) Sporophyte dependent on gametophyte (e.g., mosses) (b) Large sporophyte and small, Independent gametophyte (e.g., ferns) (c) Reduced gametophyte dependent on sporophyte (seed plants) Figure 16.14 Three variations on alternation of generations in plants. Key Haploid (n) Diploid (2n) Figure 16.14

A pine tree or other conifer is actually a sporophyte with tiny gametophytes living in cones. Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Scale Ovule-producing cones; the scales contain female gametophytes Pollen-producing cones; they produce male gametophytes Figure 16.15 A pine tree, the sporophyte, bearing two types of cones containing gametophytes Ponderosa pine Figure 16.15

A second adaptation of seed plants to dry land was the evolution of pollen. A pollen grain Is actually the much-reduced male gametophyte Houses cells that will develop into sperm Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

The third terrestrial adaptation was the development of the seed, consisting of A plant embryo A food supply packaged together within a protective coat Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Seeds Develop from structures called ovules, located on the scales of female cones in conifers Can remain dormant for long periods before they germinate, as the embryo emerges through the seed coat as a seedling Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Angiosperms Angiosperms Their success is largely due to Dominate the modern landscape Are represented by about 250,000 species Supply nearly all of our food and much of our fiber for textiles Their success is largely due to A more efficient water transport The evolution of the flower Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Flowers, Fruits, and the Angiosperm Life Cycle Flowers help to attract pollinators who transfer pollen from the sperm-bearing organs of one flower to the egg-bearing organs of another. Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Petal Stigma Anther Stamen Carpel Style Filament Ovary Ovule Sepal Figure 16.17 Structure of a flower Ovule Sepal Figure 16.17

Flowers come in many forms Figure 16.18 A diversity of flowers Pansy Bleeding heart California poppy Water lily Figure 16.18

Figure 16.19-1 Mature sporophyte plant with flowers Key Haploid (n) Figure 16.19 The angiosperm life cycle (Step 1) Key Haploid (n) Diploid (2n) Figure 16.19-1

Figure 16.19-2 Germinated pollen grain (male gametophyte) on stigma of carpel Anther at tip of stamen Pollen tube growing down style of carpel Mature sporophyte plant with flowers Ovary (base of carpel) Ovule Embryo sac (female gametophyte) Egg Two sperm nuclei Figure 16.19 The angiosperm life cycle (Step 2) Key Haploid (n) Diploid (2n) Figure 16.19-2

Figure 16.19-3 Germinated pollen grain (male gametophyte) on stigma of carpel Anther at tip of stamen Pollen tube growing down style of carpel Mature sporophyte plant with flowers Ovary (base of carpel) Ovule FERTILIZATION Endosperm Embryo sac (female gametophyte) Egg Zygote Two sperm nuclei Figure 16.19 The angiosperm life cycle (Step 3) Key Haploid (n) Diploid (2n) Figure 16.19-3

Figure 16.19-4 Germinated pollen grain (male gametophyte) on stigma of carpel Anther at tip of stamen Pollen tube growing down style of carpel Mature sporophyte plant with flowers Ovary (base of carpel) Ovule FERTILIZATION Endosperm Embryo sac (female gametophyte) Egg Zygote Two sperm nuclei Figure 16.19 The angiosperm life cycle (Step 4) Embryo (sporophyte) Key Haploid (n) Diploid (2n) Figure 16.19-4

Figure 16.19-5 Germinated pollen grain (male gametophyte) on stigma of carpel Anther at tip of stamen Pollen tube growing down style of carpel Mature sporophyte plant with flowers Ovary (base of carpel) Ovule FERTILIZATION Endosperm Embryo sac (female gametophyte) Egg Zygote Two sperm nuclei Figure 16.19 The angiosperm life cycle (Step 5) Embryo (sporophyte) Seed Key Haploid (n) Diploid (2n) Seed (develops from ovule) Fruit (develops from ovary) Figure 16.19-5

Figure 16.19-6 Germinated pollen grain (male gametophyte) on stigma of carpel Anther at tip of stamen Pollen tube growing down style of carpel Mature sporophyte plant with flowers Ovary (base of carpel) Ovule FERTILIZATION Endosperm Embryo sac (female gametophyte) Egg Zygote Two sperm nuclei Sporophyte seedling Figure 16.19 The angiosperm life cycle (Step 6) Embryo (sporophyte) Seed Germinating seed Key Haploid (n) Diploid (2n) Seed (develops from ovule) Fruit (develops from ovary) Figure 16.19-6

Although both have seeds Angiosperms enclose the seed within an ovary Gymnosperms have naked seeds Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Fruit Is a ripened ovary Helps protect the seed Increases seed dispersal Is a major food source for animals Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Wind dispersal Animal transportation Animal ingestion Figure 16.20 Figure 16.20 Fruits and seed dispersal Figure 16.20

Angiosperms and Agriculture Gymnosperms supply most of our lumber and paper. Angiosperms Provide nearly all our food Supply fiber, medications, perfumes, and decoration Agriculture is a unique kind of evolutionary relationship between plants and animals. Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Plant Diversity as a Nonrenewable Resource The exploding human population is Extinguishing plant species at an unprecedented rate Destroying fifty million acres, an area the size of the state of Washington, every year! Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Humans depend on plants for thousands of products including Food Building materials Medicines Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

Table 16.1 A Sampling of Medicines Derived from Plants

Preserving plant diversity is important to many ecosystems and humans. Scientists are now rallying to Slow the loss of plant diversity Encourage management practices that use forests as resources without damaging them Student Misconceptions and Concerns 1. Students can easily confuse animal and plant reproductive cycles. However, the unique inclusion of alternation of generations in plants (and certain algae) makes analogies and parallels challenging and potentially confusing when referencing animal life cycles. 2. Students often confuse global warming and the destruction of the ozone layer. This might be a good time to discuss or clarify global warming. The carbon removed from the air in the Carboniferous has been “locked up” in coal for about 300 million years. By burning fossil fuels, we are reintroducing carbon that has been “out of circulation.” Thus, there is a net gain in global carbon dioxide, which may act like glass in a car to reflect back heat (or glass in a greenhouse). Note that burning ethanol derived from corn does not directly contribute to global warming because the carbon in the ethanol was removed from the air only a year or two ago, instead of hundreds of millions of years ago (although the use of fossil fuels to raise, harvest, and process corn does contribute to global warming). Teaching Tips 1. The authors describe four major periods of plant evolution. The remainder of the chapter sections on plants describes these periods as they evolved in major plant groups. This is consistent with good lecture advice: Tell them what you are going to tell them, tell them, then tell them what you told them (summarize). 2. Students might enjoy the parallel between a chicken egg and the first seeds (although this is a limited analogy). Each consists of a developing embryo, enclosed in a water-resistant packet, along with a store of food. 3. The support provided by many tightly packed mosses is analogous to the collective support of the many fibers of plush carpeting. 4. Students might wonder if humans and other animals do not also qualify as having alternation of generations. Although we do have haploid gametes, the haploid and diploid stages do not include multicellular individuals. 5. Depending upon where your course is taught, coal may be an important part of the economy. The geology of these coal deposits helps us interpret the rich history of life on Earth. If you live in a coal region, consider spending additional time on how coal was deposited, why it is an important source of energy, and how the use of fossil fuels contributes to global warming. 6. As Francois Jacob suggested, evolution works as a tinkerer and not like an engineer. New forms evolve by remodeling old forms. The structure of a flower represents the remodeling of leaves, a subject which you may want to explore in additional detail as an important lesson in evolution. 7. Floral shops frequently discard magnificent flowers that are just beyond their peak. Teachers can obtain such discards for free by contacting local floral shops and sharing your educational needs. Having a variety of flowers on hand can brighten up any discussion of angiosperms. 8. Before lecturing over the examples of angiosperm and animal cooperation, let your students try to name as many as they can. They could work in small groups or do this ahead of time and bring their responses to class (or e-mail them). 9. You might have your class spend a minute just to list all of the plant-derived materials in your classroom—cotton material, wood for pencils, paper in many forms, etc. 10. The tremendous volume of pollen released into the air is apparent to anyone suffering from allergies. You might wish to have your students find the pollen counts for your area, commonly given out in weather information. It might be interesting to track the pollen counts as you go through part of the semester. 11. Depending upon where your course it taught, you can reference any local agricultural monoculture that replaced a much more diverse native ecosystem, perhaps many years ago. From old growth forest replaced with a single fast growing species, to vast fields of corn, wheat, or soybeans that replaced native prairies, students may fail to see this loss of diversity.

FUNGI Fungi Recycle vital chemical elements back to the environment in forms other organisms can assimilate Form mycorrhizae, fungus-root associations that help plants absorb from the soil Minerals Water Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

Fungi are Eukaryotes Typically multicellular More closely related to animals than plants, arising from a common ancestor about 1.5 billion years ago Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

Fungi Come in many shapes and sizes Represent more than 100,000 species Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

Budding yeast A “fairy ring” Mold Orange fungi Predatory fungus Colorized SEM Budding yeast A “fairy ring” Roundworm Body of fungus Mold Colorized SEM Orange fungi Figure 16.22 A gallery of diverse fungi Colorized SEM Predatory fungus Figure 16.22

Fungal Nutrition Fungi Are chemoheterotrophs Acquire their nutrients by absorption Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

Reproductive structure Hyphae Spore-producing structures Mycelium Figure 16.23 The fungal mycelium Mycelium Mycelium Figure 16.23

Fungal Reproduction Mushrooms Arise from an underground mycelium Mainly function in reproduction Fungi reproduce by releasing billions and trillions of spores that are produced either sexually or asexually. Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

The Ecological Impact of Fungi Fungi have An enormous ecological impact Many interactions with humans Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

Fungi as Decomposers Fungi and bacteria Are the principal decomposers of ecosystems Keep ecosystems stocked with the inorganic nutrients necessary for plant growth Without decomposers, carbon, nitrogen, and other elements would accumulate in nonliving organic matter. Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

Molds can destroy Fruit Grains Wood Human-made material Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

About 50 species of fungi are known to be parasitic in humans and other animals, causing Lung and vaginal yeast infections Athlete’s foot Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

Commercial Uses of Fungi Fungi are commercially important. Humans eat them and use them to Produce medicines such as penicillin Decompose wastes Produce bread, beer, wine, and cheeses Student Misconceptions and Concerns 1. The diverse ecological and medical roles of fungi are often underappreciated by students. Chapter 16 surveys this information well. Consider quizzing your students over the ecological importance of fungi and the medical and ecological significance of fungi to humans, before assigning or lecturing on these topics. Such exercises can generate increased student interest. 2. Students often view fungi as some type of plant. However, many differences exist (e.g., nonphotosynthetic cells surrounded by cell walls made of chitin). Consider addressing these basic differences early in your lectures to clearly distinguish fungi as a distinct group. Teaching Tips 1. The relationship between a fungus and its hyphae is analogous to a fire hydrant and the underground water pipes. 2. Consider asking your students to distinguish between fungi and animals. Both are multicellular heterotrophs lacking cellulose. Students will have to dig a little to discover that fungi have cell walls primarily composed of chitin. You might challenge them further to identify animals that also absorb their nutrients directly from their environments (e.g., tapeworms). 3. The chytrid fungus is suspected in the worldwide decline of many amphibian species. Many Internet resources are available to learn more about the impact of this fungus on amphibians.

(the fungal kind, not the chocolates) Truffles (the fungal kind, not the chocolates) Blue cheese Figure 16.26 Fungi eaten by humans Chanterelle mushrooms Figure 16.26