Chapter 29: The Evolution of Seed Plants CHAPTER 29 The Evolution of Seed Plants

Chapter 29: The Evolution of Seed Plants General Characteristics of the Seed Plants General Characteristics of the Seed Plants The Gymnosperms: Naked Seeds The Gymnosperms: Naked Seeds The Angiosperms: Flowering Plants The Angiosperms: Flowering Plants

Chapter 29: The Evolution of Seed Plants General Characteristics of the Seed Plants The seed plants are heterosporous and have greatly reduced gametophytes.The seed plants are heterosporous and have greatly reduced gametophytes. Review Figures 29.1,

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Chapter 29: The Evolution of Seed Plants 29.2 – Part 1 Figure 29.2 – Part 1 figure 29-02a.jpg

Chapter 29: The Evolution of Seed Plants 29.2 – Part 2 Figure 29.2 – Part 2 figure 29-02b.jpg

Chapter 29: The Evolution of Seed Plants General Characteristics of the Seed Plants Most modern seed plants have no swimming gametes and do not require liquid water for fertilization.Most modern seed plants have no swimming gametes and do not require liquid water for fertilization. The male gametophyte is dispersed by wind or animals.The male gametophyte is dispersed by wind or animals.7

Chapter 29: The Evolution of Seed Plants General Characteristics of the Seed Plants The seed is a well-protected resting stage that often contains food that supports the growth of the embryo.The seed is a well-protected resting stage that often contains food that supports the growth of the embryo.8

Chapter 29: The Evolution of Seed Plants The Gymnosperms: Naked Seeds The gymnosperms, once the dominant vegetation on Earth, still dominate forests in the northern parts of the Northern Hemisphere and at high elevations.The gymnosperms, once the dominant vegetation on Earth, still dominate forests in the northern parts of the Northern Hemisphere and at high elevations. No flowersNo flowers Seeds not protected by fruitSeeds not protected by fruit9

Chapter 29: The Evolution of Seed Plants The Gymnosperms: Naked Seeds The four surviving gymnosperm phyla are the Cycadophyta, Ginkgophyta, Gnetophyta, and Coniferophyta.The four surviving gymnosperm phyla are the Cycadophyta, Ginkgophyta, Gnetophyta, and Coniferophyta.10

Chapter 29: The Evolution of Seed Plants The Gymnosperms: Naked Seeds Modern gymnosperms all have abundant xylem and extensive secondary growth.Modern gymnosperms all have abundant xylem and extensive secondary growth.11

Chapter 29: The Evolution of Seed Plants The Gymnosperms: Naked Seeds Conifers have a life cycle in which naked seeds are produced on the scales of female cones.Conifers have a life cycle in which naked seeds are produced on the scales of female cones. Pollen cones are smaller than seed cones.Pollen cones are smaller than seed cones. Pollen is transferred by wind.Pollen is transferred by wind. Review Figure

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Chapter 29: The Evolution of Seed Plants The Angiosperms: Flowering Plants Angiosperms are distinguished by double fertilization, as are the Gnetophyta.Angiosperms are distinguished by double fertilization, as are the Gnetophyta. Double fertilization results in a triploid nutritive tissue, the endosperm.Double fertilization results in a triploid nutritive tissue, the endosperm. Review Figure

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Chapter 29: The Evolution of Seed Plants The Angiosperms: Flowering Plants Angiosperms are characterized by the production of flowers and fruits.Angiosperms are characterized by the production of flowers and fruits. Ovules and seeds are enclosed by a carpel.Ovules and seeds are enclosed by a carpel.16

Chapter 29: The Evolution of Seed Plants The Angiosperms: Flowering Plants The vascular tissues of angiosperms contain three characteristic cell types:The vascular tissues of angiosperms contain three characteristic cell types:  vessel elements  fibers  companion cells. 17

Chapter 29: The Evolution of Seed Plants The Angiosperms: Flowering Plants Flowers are made up of various combinations of carpels, stamens, petals, and sepals.Flowers are made up of various combinations of carpels, stamens, petals, and sepals. Perfect flowers have both carpels and stamens.Perfect flowers have both carpels and stamens. Review Figure

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Chapter 29: The Evolution of Seed Plants The Angiosperms: Flowering Plants Monoecious plant species have both female and male flowers on one plant.Monoecious plant species have both female and male flowers on one plant. In dioecious species, male and female plants are separate.In dioecious species, male and female plants are separate.20

Chapter 29: The Evolution of Seed Plants The Angiosperms: Flowering Plants Carpels and stamens may have evolved from leaflike structures.Carpels and stamens may have evolved from leaflike structures. Review Figure

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Chapter 29: The Evolution of Seed Plants The Angiosperms: Flowering Plants Amborella, a tropical shrub, is the sole living representative of the first angiosperm lineage.Amborella, a tropical shrub, is the sole living representative of the first angiosperm lineage.23

Chapter 29: The Evolution of Seed Plants The Angiosperms: Flowering Plants There are two major lineages of flowering plants: monocots and eudicots.There are two major lineages of flowering plants: monocots and eudicots. Review Figure

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Chapter 29: The Evolution of Seed Plants The Angiosperms: Flowering Plants The evolutionary origin of the angiosperms remains a mystery.The evolutionary origin of the angiosperms remains a mystery.26