Why do you think that plants such as these are essential for most life on Earth? • In what major way does the top pair of plants differ from the bottom pair?
Unit Overview – pages 556 - 557 Plants The Diversity of Plants Nonvascular Plants Non-Seed Vascular Plants
Section 22.1 Summary – pages 577 - 580 What is a nonvascular plant? • Nonvascular plants are mosses, liverworts and hornworts.
Section 22.1 Summary – pages 577 - 580 What is a nonvascular plant? • Nonvascular plants can only pass materials from one cell to the next.
Section 22.1 Summary – pages 577 - 580 • Nonvascular plants only have their cell walls to provide support, so they are small, low plants.
Section 22.1 Summary – pages 577 - 580 • Nonvascular plants lack roots, but can obtain water and minerals from their surroundings.
Section 22.1 Summary – pages 577 - 580 Alternation of generations • Nonvascular plants can only grow in moist environments because they must have a thin film of water for sperm to reach the egg. • Nonvascular plants produce spores.
Section 22.1 Summary – pages 577 - 580 Adaptations in Bryophyta • There are several divisions of nonvascular plants. • The first division you’ll study are the mosses, or bryophytes. • Mosses are small plants with leafy stems.
Adaptations in Bryophyta • The leaves of mosses are usually one cell thick. • Mosses usually grow in dense carpets of hundreds of plants.
Section 22.1 Summary – pages 577 - 580 Adaptations in Hepaticophyta • Another division of nonvascular plants is the liverworts, or hepaticophytes. • Liverworts are small plants that usually grow in clumps or masses in moist habitats.
Adaptations in Anthocerophyta • Anthocerophytes are the smallest division of nonvascular plants, currently consisting of only about 100 species. • Also known as hornworts, these nonvascular plants are similar to liverworts in several respects.
Section 22.2 Summary – pages 581 - 587 What is a non-seed vascular plant? • The obvious difference between a vascular and a nonvascular plant is the presence of vascular tissue. • Ferns, club mosses and horsetails are non-seed vascular plants. • Ferns, club mosses and horsetails reproduce using spores and still need to grow in moist surroundings.
Section 22.2 Summary – pages 581 - 587 Fern Structures • In most ferns, the main stem is underground. • A rhizome is the thick, underground stem of a fern Fronds Rhizome Root
Fern Structures • The leaves of a fern are called fronds and grow upward from the rhizome. • Spores develop on the underside of mature fronds.
Section 22.2 Summary – pages 581 - 587 Adaptations in Lycophyta • Lycophytes are commonly called club mosses and spike mosses.
Section 22.2 Summary – pages 581 - 587 Adaptations in Arthrophyta • Arthrophytes, or horsetails, represent a second group of ancient vascular plants.
Section 22.2 Summary – pages 581 - 587 Adaptations in Pterophyta • Ferns range in size from a few meters tall, like tree ferns, to small, floating plants that are only a few centimeters in diameter.
Section 1 Check Question 1 The only plants that have a dominant gametophyte generation are the _______. A. vascular plants B. flowering plants C. nonvascular plants D. ferns The answer is C.
Section 1 Check Question 2 The rhizoid in mosses has a function comparable to _______. A. The flower in flowering plants B. The cone in conifers C. The root in vascular plants D. The leaf in cycads
Section 1 Check The answer is C. Rhizoids anchor the stems of mosses to the soil as roots do in other plants.
Section 2 Check Question 1 Egg Using the figure, which structure would you assume the sporophyte grows from? Archegonium Prothallus Sperm Rhizoids Antheridium
Section 2 Check The answer is the archegonium. Sperm travel from the antheridium to the archegonium where they unite with an egg and form a zygote. The zygote grows into the sporophyte. Egg Archegonium Prothallus Sperm Rhizoids Antheridium
Section 2 Check Question 2 A compact cluster of spore-bearing leaves is called a _______. A. thallus C. prothallus B. rhizoid D. strobilus The answer is D.
Unit Overview – pages 556 - 557 Plants The Diversity of Plants That Characteristics of Seed Plants
Section 22.3 Summary – pages 588 - 597 What is a seed plant? • All seed plants have vascular tissue, use seed to reproduce and have leaves, stems and roots. • Seed plants do not need water in their environment to reproduce.
Section 21.1 Summary – pages 559 - 563 Reproductive strategies • A seed is a plant organ that contains an embryo, along with a food supply, and is covered by a protective coat. • Embryo • Seed Coat • Food Supply
Section 22.3 Summary – pages 588 - 597 Fertilization and reproduction • The embryo is a fertilized egg that the young plant develops from • Embryos of seed plants include one or more cotyledons (seed leaves).
Section 22.3 Summary – pages 588 - 597 Fertilization and reproduction • Cotyledons store or absorb food for the developing embryo. Cotyledon Seed coat Cotyledons
Section 22.3 Summary – pages 588 - 597 Advantages of seeds • The seed coat is the outer covering of the seed. • Ex. “skins” on peanuts, beans, etc. Embryo Seed coat Food supply • The scattering of seeds is called seed dispersal.
Seed Dispersal • Some seeds are spiny and hitch rids on the fur of animals. • Some seeds rely on oceans, rivers and streams of dispersal. • The wind carries some seeds through the air. • Some plants shoot their seeds out when their pods explode. • Some rely on animals to eat them and pass them out later. Ex. acorn or apple
Section 22.3 Summary – pages 588 - 597 What are gymnosperms? • Gymnosperms are plants whose seeds are not protected by a fruit. • Many gymnosperms have needlelike or scalelike leaves. • Most gymnosperms are trees, a few are shrubs or vines.
Section 22.3 Summary – pages 588 - 597 Cycads • Grow mainly in tropical and subtropical areas. • Look like palm trees with cones.
Section 22.3 Summary – pages 588 - 597 Gingko • All ginkgoes are cultivated trees, and they are not known to exist in the wild. • Only one species exists. • Ginkgoes often are planted in urban areas because they tolerate smog and pollution.
Section 22.3 Summary – pages 588 - 597 Gnetophytes • Found only in the hot, dry deserts of South Africa, deserts of the western United States, and the tropical rain forests. • The plants that grow in South Africa grow close to the ground, have large tuberous roots, and may live 1000 years.
Section 22.3 Summary – pages 588 - 597 • Cone-bearing plants • Cones are either male or female • Some trees produce both cones, some only produce one • Largest and most diverse group of gymnosperms • Most are evergreen Confiers
Section 22.3 Summary – pages 588 - 597 Deciduous trees lose their leaves • A few conifersare deciduous. • Deciduous plantsdrop all their leaves each fall or when water is scarce or unavailable.
Section 22.3 Summary – pages 588 - 597 Diversity of seed plants • Flowering plants, also called angiosperms, produce seeds enclosed within a fruit. • The fruit is the ripened ovary of a flower.
Section 22.3 Summary – pages 588 - 597 Diversity of seed plants • The fruit provides protection for seeds and aids in seed dispersal. • The Anthophyta division contains all species of flowering plants.
Section 24.2 Summary – pages 641-645 The structure of a flower • The flower contains the reproductive structures that the fruit develops from.
Section 22.3 Summary – pages 588 - 597 Seed plants produce spores • The male structure is the stamen, which consists of a filament and an anther where the pollen grains are produced. anther stamen filament
Section 22.3 Summary – pages 588 - 597 Seed plants produce spores • The pollen grain is the male gametophyte that includes sperm cells, nutrients, and a protective outer covering. anther stamen filament
Section 22.3 Summary – pages 588 - 597 Seed plants produce spores • The female structure is the pistil, which consists of the stigma, style, and ovary where the ovule is produced. anther stigma stamen filament style pistil ovary ovule
Section 22.3 Summary – pages 588 - 597 Seed plants produce spores • The ovule is the structure that contains the female gametophyte, which produces the egg cell. anther stigma stamen filament style pistil ovary ovule
Section 22.3 Summary – pages 588 - 597 Moncots and dicots • The division Anthophyta is divided into two classes: monocotyledons and dicotyledons. • Monocotyledonshave one seed leaf. • Dicotyledons have two seed leaves.
Section 23.2 Summary – pages 612-621 The structure of roots • Root hairs Xylem and phloem are located in the center of the root. • Xylem • Phloem The arrangement of xylem and phloem tissues accounts for one of the major differences between monocots and dicots. • Pericycle • Endodermis • Apical meristem • Root cap
Section 23.2 Summary – pages 612-621 The structure of roots In dicot roots, the xylem forms a central star-shaped mass with phloem cells between the rays of the star.
The structure of roots • Monocot roots usually have strands of xylem that alternate with strands of phloem.
Section 23.2 Summary – pages 612-621 Internal structure In most dicots, xylem and phloem are in a circle of vascular bundles that form a ring in the cortex. • Vascular bundle
Internal structure • The vascular bundles of most monocots are scattered throughout the stem. • Vascular bundles