Plants Have Changed the World - PDF Free Download

Chapter 19 Plants Man: G. R. "Dick" Roberts/Natural Sciences Image Library Copyright McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.

Plants Have Changed the World Members of kingdom Plantae are nearly everywhere. Snow: Design Pics/Carson Ganci/Getty Images RF; Prairie: Tetra Images/Tetra Images/Corbis RF; Forest: Ted Section 19.1 Figure 19.1 Mead/Getty Images RF

Plants Have Changed the World Plants harness the energy that sustains ecosystems. They also release O 2, which consumers use for respiration. Snow: Design Pics/Carson Ganci/Getty Images RF; Prairie: Tetra Images/Tetra Images/Corbis RF; Forest: Ted Section 19.1 Figure 19.1 Mead/Getty Images RF

Highlights in the History of Plants Plants arose about 475 million years ago from ancestors resembling green algae. Section 19.1 Cotton: S. Solum/PhotoLink/Getty Images RF

Highlights in the History of Plants Plants arose about 475 million years ago. Section 19.1

Highlights in the History of Plants Major evolutionary events in plants include the origins of vascular tissue, pollen and seeds, and flowers. Section 19.1

Highlights in the History of Plants The presence or absence of vascular tissue, pollen and seeds, and flowers defines each plant group. Section 19.1

Highlights in the History of Plants The presence or absence of vascular tissue, pollen and seeds, and flowers defines each plant group. Section 19.1 Figure 19.3

Highlights in the History of Plants Bryophytes have no vascular tissue, seeds, or flowers. Mosses are bryophytes. Section 19.1 Figure 19.3

Highlights in the History of Plants The origin of vascular tissue, which transports water and nutrients in the plant, allowed plants to grow taller. Taller plants reach above their neighbors in the struggle for sunlight. Section 19.1 Figure 19.3

Highlights in the History of Plants Vascular tissue consists of phloem and xylem. Phloem transports sugars. Xylem transports water. Section 19.1 Stem cross section: Dr. John D. Cunningham/Visuals Unlimited Figures 19.3, 19.4

Highlights in the History of Plants Lignin is a complex polymer that strengthens cell walls in vascular tissue. Section 19.1 Stem cross section: Dr. John D. Cunningham/Visuals Unlimited Figures 19.3, 19.4

Highlights in the History of Plants Modifications in vascular tissue led to the evolution of seedless vascular plants, like ferns. Section 19.1 Figure 19.3

Highlights in the History of Plants The origin of seeds dormant, protected plant embryos with a nutrient supply was also adaptive. Seeds might travel far from the parent and only germinate when conditions are favorable. Section 19.1 Figure 19.3

Highlights in the History of Plants Gymnosperms are plants with vascular tissue and seeds, such as pine trees. Cone scale Seed Section 19.1 Pine cones: Westend61/Alamy RF Figures 19.3, 19.4

Highlights in the History of Plants More recently, the origin of flowers and fruits introduced new reproductive adaptations. Angiosperms are flowering plants. Section 19.1 Figure 19.3

Highlights in the History of Plants More recently, the origin of flowers and fruits introduced new reproductive adaptations. Angiosperms are flowering plants. Seed contains embryo and its food supply Fertilized flowers develop into fruits that protect and disperse seeds Section 19.1 Pea pods: Corbis RF Figures 19.3, 19.4

Clicker Question #1 A newly discovered plant in the rain forest has xylem and seeds, but no flowers. What is it? A. a bryophyte B. a seedless vascular plant C. a gymnosperm D. an angiosperm Flower: Doug Sherman/Geofile/RF

All Plants Have Similar Life Cycles The similarity among plant life cycles is evidence that all plants share a common ancestor. Section 19.1 Figure 19.5

All Plants Have Similar Life Cycles The plant life cycle is called alternation of generations, in which a multicellular diploid stage alternates with a multicellular haploid stage. Section 19.1 Figure 19.5

All Plants Have Similar Life Cycles A zygote develops by mitotic cell division into a multicellular, diploid sporophyte. Section 19.1 Figure 19.5

All Plants Have Similar Life Cycles The sporophyte produces haploid spores by meiosis. Section 19.1 Figure 19.5

All Plants Have Similar Life Cycles Haploid spores divide by mitosis into a multicellular, haploid gametophyte. Section 19.1 Figure 19.5

All Plants Have Similar Life Cycles The haploid gametophyte produces gametes by mitotic cell division. Section 19.1 Figure 19.5

All Plants Have Similar Life Cycles These sex cells fuse at fertilization, forming a diploid zygote and starting the cycle anew. Section 19.1 Figure 19.5

All Plants Have Similar Life Cycles The sporophyte and gametophyte shown in this generalized plant life cycle are those of a seedless vascular plant. Section 19.1 Figure 19.5

All Plants Have Similar Life Cycles Substituting images in the alternation of generations produces diagrams of other plant life cycles. Section 19.1 Figure 19.21

All Plants Have Similar Life Cycles Note that the size of the sporophyte relative to the gametophyte varies through plant groups. Sporophyte Gametophyte Section 19.1 Figure 19.21

Clicker Question #2 How many of the items in the following list are haploid? zygote, gamete, sporophyte, spore, gametophyte A. one B. two C. three D. four E. five Flower: Doug Sherman/Geofile/RF

19.1 Mastering Concepts What features differentiate the four major groups of plants? Man: G. R. "Dick" Roberts/Natural Sciences Image Library

Bryophytes Are the Simplest Plants Section 19.2 Figure 19.3

Bryophytes Are the Simplest Plants Bryophytes are seedless plants that lack vascular tissue. They also lack true leaves and roots. Section 19.2 Liverwort: Edward S. Ross; Hornwort: William E. Ferguson; Moss: Steven P. Lynch/The Mcgraw-Hill Companies Figure 19.7

Bryophytes Are the Simplest Plants Materials move from cell to cell within the plant by diffusion and osmosis. Section 19.2 Liverwort: Edward S. Ross; Hornwort: William E. Ferguson; Moss: Steven P. Lynch/The Mcgraw-Hill Companies Figure 19.7

Bryophytes Are the Simplest Plants Examples of bryophytes include: Liverworts Hornworts Mosses Section 19.2 Liverwort: Edward S. Ross; Hornwort: William E. Ferguson; Moss: Steven P. Lynch/The McGraw-Hill Companies Figure 19.7

Bryophytes Are the Simplest Plants The bryophyte life cycle is an alternation of generations. Section 19.2

Bryophytes Are the Simplest Plants Sporophyte Haploid spores form by meiosis in the sporophyte tip. Section 19.2 Figure 19.9

Bryophytes Are the Simplest Plants Sporophyte Spores are released from the sporophyte. Section 19.2 Figure 19.9

Bryophytes Are the Simplest Plants Sporophyte Each spore might develop by mitosis into a gametophyte. Young gametophyte Section 19.2 Figure 19.9

Bryophytes Are the Simplest Plants Sporophyte A mature gametophyte is either male or female. Section 19.2 Female Male Figure 19.9

Bryophytes Are the Simplest Plants Sporophyte Gametophytes produce gametes by mitosis. Sperm cells Section 19.2 Egg cell Female Male Figure 19.9

Bryophytes Are the Simplest Plants Sporophyte Gametes travel from male to female gametophytes in water. Sperm cells Section 19.2 Egg cell Female Male Figure 19.9

Bryophytes Are the Simplest Plants Sporophyte When sperm meets egg, a zygote forms within the female gametophyte. Sperm cells Zygote Section 19.2 Egg cell Female Male Figure 19.9

Bryophytes Are the Simplest Plants Sporophyte The zygote develops by mitosis into a sporophyte, and the cycle begins again. Sperm cells Zygote Section 19.2 Egg cell Female Male Figure 19.9

Bryophytes Are the Simplest Plants Bryophyte life cycle overview Section 19.2 Bryophytes: Ed Reschke Figure 19.9

Clicker Question #3 Meiosis occurs in the structure indicated by the arrow. What will the structure produce? A. spores B. phloem C. gametes D. pollen Flower: Doug Sherman/Geofile/RF; Moss: Steven P. Lynch/The McGraw-Hill Companies

19.2 Mastering Concepts Name two reasons mosses usually live in moist, shady habitats. Man: G. R. "Dick" Roberts/Natural Sciences Image Library

Seedless Vascular Plants Section 19.3 Figure 19.3

Seedless Vascular Plants Seedless vascular plants have xylem and phloem but not seeds. These plants typically have true roots, stems, and leaves. Section 19.3 Whisk fern: W. Ormerod/Visuals Unlimited; Horsetail: Ed Reschke; Beech fern: Rod Planck/Science Source Figure 19.10

Seedless Vascular Plants Examples of seedless vascular plants include: Lycopods (not shown) Whisk ferns True ferns Horsetails Section 19.3 Whisk fern: W. Ormerod/Visuals Unlimited; Horsetail: Ed Reschke; Beech fern: Rod Planck/Science Source Figure 19.10

Seedless Vascular Plants The seedless vascular plant life cycle is an alternation of generations. Section 19.3

Seedless Vascular Plants Sporophyte Haploid spores form by meiosis in sporangia on sporophyte leaves. Section 19.3 Figure 19.11

Seedless Vascular Plants Sporophyte Spores are released from the sporangia. Sporangium Spores Section 19.3 Figure 19.11

Seedless Vascular Plants Sporophyte Each spore might develop by mitosis into a gametophyte. Sporangium Spores Gametophyte Section 19.3 Figure 19.11

Seedless Vascular Plants Sporophyte Gametophytes produce gametes by mitosis. Egg cell Sporangium Spores Sperm cell Gametophyte Section 19.3 Figure 19.11

Seedless Vascular Plants Sporophyte Gametes travel from male to female gametophytes in water. Egg cell Sporangium Spores Sperm cell Gametophyte Section 19.3 Figure 19.11

Seedless Vascular Plants Sporophyte When sperm meets egg, a zygote forms within the gametophyte tissue. Sperm cell Egg cell Zygote Sporangium Spores Gametophyte Section 19.3 Figure 19.11

Seedless Vascular Plants Sporophyte The zygote develops by mitosis into a sporophyte, and the cycle begins again. Sperm cell Egg cell Zygote Sporangium Spores Gametophyte Section 19.3 Figure 19.11

Seedless Vascular Plants Seedless vascular plant life cycle overview Section 19.3 Spores: Ed Reschke/Peter Arnold/Getty Images; Fern gametophyte: Les Hickok and Thomas Warne, C-Fern Figure 19.11

19.3 Mastering Concepts How are seedless vascular plants similar to and different from bryophytes? Man: G. R. "Dick" Roberts/Natural Sciences Image Library

Gymnosperms Are Naked Seed Plants Section 19.4 Figure 19.3

Gymnosperms Are Naked Seed Plants The sporophytes of most gymnosperms are woody trees or shrubs. Reproductive structures and leaf types are diverse. Section 19.4 Cycad tree: Alena Brozova/Alamy; cycad seed: Pat Pendarvis; ginko tree: Light of Peace/Flickr/Getty Images RF; ginko seed: G. R. "Dick" Roberts/Natural Sciences Image Library; conifer tree: Jack Dykinga/Nature Picture Library; pine cone: Ed Reschke/Peter Arnold/Getty Images; ephedra: Gerald & Buff Corsi/Visuals Unlimited; ephedra reproductive structures: Edward S. Ross Figure 19.12

Gymnosperms Are Naked Seed Plants Gymnosperms are divided into four groups: Cycads Ginkgo Conifers Gnetophytes Section 19.4 Cycad tree: Alena Brozova/Alamy; cycad seed: Pat Pendarvis; ginko tree: Light of Peace/Flickr/Getty Images RF; ginko seed: G. R. "Dick" Roberts/Natural Sciences Image Library; conifer tree: Jack Dykinga/Nature Picture Library; pine cone: Ed Reschke/Peter Arnold/Getty Images; ephedra: Gerald & Buff Corsi/Visuals Unlimited; ephedra reproductive structures: Edward S. Ross Figure 19.12

Gymnosperms Are Naked Seed Plants Gymnosperm life cycle is an alternation of generations. Section 19.4

Gymnosperms Are Naked Seed Plants Sporophyte Female cones Male cones Haploid spores form by meiosis in sporophyte cones. Section 19.4 Figure 19.13

Gymnosperms Are Naked Seed Plants Sporophyte Female cones Male cones Male cones produce microspores by meiosis on cone scales. Microspores Section 19.4 Figure 19.13

Gymnosperms Are Naked Seed Plants Sporophyte Female cones Male cones Ovules on female cone scales produce megaspores by meiosis. Microspores Megaspores (three will degenerate) Section 19.4 Figure 19.13

Gymnosperms Are Naked Seed Plants Sporophyte Female cones Male cones Spores develop by mitosis into microscopic gametophytes. Pollen grain Microspores Megaspores (three will degenerate) Egg cells Section 19.4 Figure 19.13

Gymnosperms Are Naked Seed Plants Sporophyte Female cones Male cones Gametophytes unite at pollination. Pollen grain Microspores Megaspores (three will degenerate) Egg cells Section 19.4 Figure 19.13

Gymnosperms Are Naked Seed Plants Sporophyte Female cones Male cones A pollen grain germinates, producing a pollen tube. Sperm nuclei Pollen tube Pollen grain Egg cells Microspores Megaspores (three will degenerate) Section 19.4 Figure 19.13

Gymnosperms Are Naked Seed Plants Sporophyte Female cones Male cones Sperm nuclei travel through the pollen tube to the egg cells. Fertilization occurs. Sperm nuclei Pollen tube Pollen grain Egg cells Microspores Megaspores (three will degenerate) Section 19.4 Figure 19.13

Gymnosperms Are Naked Seed Plants Sporophyte Seeds Female cones Male cones The resulting zygote grows mitotically into an embryo, inside a seed, on a female cone scale. Sperm nuclei Pollen tube Zygote Microspores Pollen grain Egg cells Megaspores (three will degenerate) Section 19.4 Figure 19.13

Gymnosperms Are Naked Seed Plants Sporophyte Seeds Female cones Male cones The seed germinates and grows mitotically into a mature sporophyte. Sperm nuclei Pollen tube Zygote Microspores Pollen grain Egg cells Megaspores (three will degenerate) Section 19.4 Figure 19.13

Gymnosperms Are Naked Seed Plants Gymnosperm life cycle overview Section 19.4 Figure 19.13

Clicker Question #4 How is gymnosperm reproduction different from that of ferns? A. Gymnosperms produce seeds; ferns don t. B. Gymnosperms produce swimming sperm; ferns don t. C. Gymnosperms produce zygotes; ferns don t. D. Gymnosperms don t produce spores; ferns do. Flower: Doug Sherman/Geofile/RF

19.4 Mastering Concepts What happens during and after pollination in gymnosperms? Man: G. R. "Dick" Roberts/Natural Sciences Image Library

Angiosperms Produce Seeds in Fruits Section 19.5 Figure 19.3

Angiosperms Produce Seeds in Fruits Today, most plant species have reproductive structures called flowers, which develop into seedtoting fruits. Section 19.5 Red maple flower: Dwight Kuhn; cattails: Hans Reinhard/Okapia/Science Source; bee: McGraw-Hill Education; banana flower: Igor Prahin/Flickr Open/Getty Images RF Figure 19.16

Angiosperms Produce Seeds in Fruits Flowers produce pollen and eggs; wind or animals usually carry pollen from plant to plant. Fruits protect the seeds and disperse them to new habitats. Section 19.5 Red maple flower: Dwight Kuhn; cattails: Hans Reinhard/Okapia/Science Source; bee: McGraw-Hill Education; banana flower: Igor Prahin/Flickr Open/Getty Images RF Figure 19.16

Angiosperms Produce Seeds in Fruits Variation in flowers and fruits is the result of millions of years of evolution. Section 19.5 Red maple flower: Dwight Kuhn; cattails: Hans Reinhard/Okapia/Science Source; bee: McGraw-Hill Education; banana flower: Igor Prahin/Flickr Open/Getty Images RF Figure 19.16

Angiosperms Produce Seeds in Fruits Scientists classify the diverse angiosperms into several taxa, notably the eudicots and monocots. Section 19.5 Figure 19.14

Angiosperms Produce Seeds in Fruits The angiosperm life cycle is an alternation of generations. Section 19.5

Angiosperms Produce Seeds in Fruits Sporophyte Pollen sac Ovule Haploid spores form by meiosis in flowers. Section 19.5 Figure 19.15

Angiosperms Produce Seeds in Fruits Sporophyte Each mother cell in a pollen sac divides into four microspores. Microspores Pollen sac Ovule Section 19.5 Figure 19.15

Angiosperms Produce Seeds in Fruits Sporophyte Each mother cell in an ovule divides into four megaspores. Only one persists. Microspores Pollen sac Ovule Megaspores (three degenerate) Section 19.5 Figure 19.15

Angiosperms Produce Seeds in Fruits Sporophyte Spores divide mitotically into microscopic gametophytes. Pollen grains Microspores Pollen sac Ovule Megaspores (three degenerate) Section 19.5 Ovule Polar nuclei Egg Figure 19.15

Angiosperms Produce Seeds in Fruits Sporophyte During pollination, a pollen grain lands on a stigma. The pollen grain germinates, producing a pollen tube. Pollen grains Microspores Pollen sac Ovule Megaspores (three degenerate) Section 19.5 Ovule Polar nuclei Egg Figure 19.15

Angiosperms Produce Seeds in Fruits Sporophyte Sperm nuclei travel through the pollen tube and fertilize the egg and polar nuclei. Endosperm nucleus (3n) Zygote (2n) Pollen tube Pollen grains Microspores Pollen sac Ovule Megaspores (three degenerate) Section 19.5 Ovule Polar nuclei Egg Figure 19.15

Angiosperms Produce Seeds in Fruits Sporophyte The zygote develops into an embryo, and the endosperm provides its food. Endosperm nucleus (3n) Zygote (2n) Pollen tube Pollen grains Microspores Pollen sac Ovule Megaspores (three degenerate) Section 19.5 Ovule Polar nuclei Egg Figure 19.15

Angiosperms Produce Seeds in Fruits Sporophyte Seeds contain the embryo and endosperm; part of the flower develops into an enclosing fruit. Endosperm nucleus (3n) Zygote (2n) Pollen tube Pollen grains Ovule Microspores Pollen sac Polar nuclei Egg Ovule Megaspores (three degenerate) Section 19.5 Figure 19.15

Angiosperms Produce Seeds in Fruits Sporophyte Seeds germinate into young sporophytes, and the cycle begins again. Endosperm nucleus (3n) Zygote (2n) Pollen grains Microspores Pollen sac Ovule Pollen tube Megaspores (three degenerate) Section 19.5 Ovule Polar nuclei Egg Figure 19.15

Angiosperms Produce Seeds in Fruits Angiosperm life cycle overview Section 19.5 Figure 19.15

Clicker Question #5 In the angiosperm life cycle, the seed is analogous to the in the human life cycle. A. male reproductive organs B. female reproductive organs C. fetus D. sperm cell E. egg cell Flower: Doug Sherman/Geofile/RF

19.5 Mastering Concepts In what ways are the life cycles of angiosperms similar to and different from those of conifers? Man: G. R. "Dick" Roberts/Natural Sciences Image Library

Investigating Life: Genetic Messages From Ancient Ecosystems Frozen soils preserve DNA from organisms that lived long ago. Section 19.6 Drilling: Courtesy of K. Schaefer Figure 19.17

Investigating Life: Genetic Messages From Ancient Ecosystems Researchers drill through the permafrost to collect DNA that will help them learn about ancient ecosystems. Section 19.6 Drilling: Courtesy of K. Schaefer Figure 19.17

Investigating Life: Genetic Messages From Ancient Ecosystems Their data reveal how a plant community changed over many thousands of years. Section 19.6 Figure 19.18