chapter 29: the evolution of seed plants chapter 29 the evolution of seed plants

Chapter 29: The Evolution of Seed Plants

CHAPTER 29The Evolution of Seed

Plants


Chapter 29: The Evolution of Seed PlantsGeneral Characteristics of the Seed PlantGeneral Characteristics of the Seed Plantss

The Gymnosperms: Naked SeedsThe Gymnosperms: Naked Seeds

The Angiosperms: Flowering PlantsThe Angiosperms: Flowering Plants


General Characteristics of the Seed Plants

• The seed plants are heterosporous and The seed plants are heterosporous and have greatly reduced gametophytes. have greatly reduced gametophytes.

Review Figures Review Figures 29.129.1, , 29.229.2

33


29.1

Figure 29.1Figure 29.1

figure 29-01.jpg


29.2 – Part 1

Figure 29.2 – Part 1Figure 29.2 – Part 1

figure 29-02a.jpg


29.2 – Part 2



figure 29-02b.jpg



• Most modern seed plants have no Most modern seed plants have no swimming gametes and do not require swimming gametes and do not require liquid water for fertilization. liquid water for fertilization.

• The male gametophyte is dispersed by The male gametophyte is dispersed by wind or animals.wind or animals.

77



• TheThe seed is a well-protected resting seed is a well-protected resting stage that often contains food that stage that often contains food that supports the growth of the embryo.supports the growth of the embryo.

88


The Gymnosperms: Naked Seeds

• The gymnosperms, once the dominant The gymnosperms, once the dominant vegetation on Earth, still dominate vegetation on Earth, still dominate forests in the northern parts of the forests in the northern parts of the Northern Hemisphere and at high Northern Hemisphere and at high elevations.elevations.

• No flowersNo flowers• Seeds not protected by fruitSeeds not protected by fruit

99



• The four surviving gymnosperm phyla The four surviving gymnosperm phyla are the Cycadophyta, Ginkgophyta, are the Cycadophyta, Ginkgophyta, Gnetophyta, and Coniferophyta.Gnetophyta, and Coniferophyta.

1010



• Modern gymnosperms all have Modern gymnosperms all have abundant xylem and extensive abundant xylem and extensive secondary growth.secondary growth.

1111



• Conifers have a life cycle in which Conifers have a life cycle in which naked seeds are produced on the naked seeds are produced on the scales of female cones. scales of female cones.

• Pollen cones are smaller than seed Pollen cones are smaller than seed cones. cones.

• Pollen is transferred by wind. Pollen is transferred by wind.

Review Figure Review Figure 29.529.5

1212


29.5


figure 29-05.jpg


The Angiosperms: Flowering Plants

• Angiosperms are distinguished by Angiosperms are distinguished by double fertilization, as are the double fertilization, as are the Gnetophyta. Gnetophyta.

• Double fertilization results in a triploid Double fertilization results in a triploid nutritive tissue, the endosperm. nutritive tissue, the endosperm.


1414


29.10


figure 29-10.jpg



• Angiosperms are characterized by the Angiosperms are characterized by the production of flowers and fruits. production of flowers and fruits.

• Ovules and seeds are enclosed by a Ovules and seeds are enclosed by a carpel.carpel.

1616



• The vascular tissues of angiosperms The vascular tissues of angiosperms contain three characteristic cell types:contain three characteristic cell types: vessel elements vessel elements fibersfibers companion cells.companion cells.

1717



• Flowers are made up of various Flowers are made up of various combinations of carpels, stamens, combinations of carpels, stamens, petals, and sepals. petals, and sepals.

• Perfect flowers have both carpels and Perfect flowers have both carpels and stamens. stamens.



29.618


figure 29-06.jpg



• Monoecious plant species have both Monoecious plant species have both female and male flowers on one plant. female and male flowers on one plant.

• In dioecious species, male and female In dioecious species, male and female plants are separate.plants are separate.

2020



• Carpels and stamens may have Carpels and stamens may have evolved from leaflike structures. evolved from leaflike structures.


2121


29.9


figure 29-09.jpg



• Amborella, a tropical shrub, is the sole Amborella, a tropical shrub, is the sole living representative of the first living representative of the first angiosperm lineage.angiosperm lineage.

2323



• There are two major lineages of There are two major lineages of flowering plants: monocots and flowering plants: monocots and eudicots. eudicots.


2424


29.13


figure 29-13.jpg



• The evolutionary origin of the The evolutionary origin of the angiosperms remains a mystery.angiosperms remains a mystery.

2626

chapter 29: the evolution of seed plants chapter 29 the evolution of seed plants

Documents