1. Sylvia S. Mader Copyright © The McGraw Hill Companies Inc. Permission required for reproduction or display PowerPoint® Lecture Slides are prepared by Dr. Isaac Barjis, Biology Instructor BIOLOGY 10th Edition Plant Evolution and Diversity Chapter 23: pp. 408 - 432 1 a. A northern coniferous forest of evergreen treesb. Cones of lodgepole pine, Pinus contortac. Fleshy seed cones of juniper, Juniperus seed cones pollen cones seed cones Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a: © Corbis Royalty Free; b: © Walt Anderson/Visuals Unlimited; c: © The McGraw Hill Companies, Inc./Evelyn Jo Johnson, photographer

2. 3 Evolutionary History of Plants Plants are multicellular, photosynthetic eukaryotes. Plants evolution is marked by adaptations to a land existence. A land environment does offer certain advantages. Plentiful light for photosynthesis Carbon dioxide is present in higher concentrations and diffuses more readily in air than in water.

3. 4 A land environment does offer certain advantages Constant threat of desiccation (drying out). Protect all phases of reproduction (sperm, egg, embryo) from drying out Seed plants disperse their embryos within the seed, which provides the embryo with food within a protective seed coat. The water environment provides plentiful water. support for the body of the plant.

4. Nonvascular Plants - have small reduced leaves, no vascular tissue(veins to carry water) no true roots, and reproduce by spores or flagellated cells that travel through water. –Bryophyta (mosses) Vascular Plants - have true roots, stems, and leaves with vascular tissue. Xylem- water and minerals. Phloem- transports carbohydrates –seedless plants club moss Ferns –seed plants Gymnosperms - naked seeds –Conifer- needle or scale leaf, cones Angiosperms - flowering plants »Monocots- parallel veins, petals in 3‘s »Dicots- net veins, petals in 4’s or 5’s PLANT OUTLINE

5. Non-Vascular vs. Vascular –Water movement by osmosis –Solutes move by diffusion –Plants not very large, all parts must be near their water source –Water and solutes moved through special cells called xylem –Sugar transported by special cells called phloem –Plants can be 300’ tall and parts can be distant from water source

6. 9 Alternation of Generations Life cycle involves alternation of generations Multicellular 1n individuals (gametophytes) produce multicellular 2n individuals (sporophytes) Multicellular 2n individuals (sporophytes) produce multicellular 1n individuals (gametophytes) Sporophyte (2n): Multicellular individual that produces spores by meiosis Spore is haploid cell that will become the gametophyte Gametophyte (1n): Multicellular individual that produces gametes Gametes fuse in fertilization to form zygote Zygote is a diploid cell that will become the sporophyte

7. 10 Alternation of Generations zygote (2n) spore (n) gametes (n) diploid (2n) MEIOSIS haploid (n) Mitosis sporangium (2n) sporophyte (2n) FERTILIZATION gametophyte (n) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

8. 11 Alternation of Generations Appearance of generations varies widely In ferns, female portions are archegonia and are fertilized by flagellated sperm In angiosperm, female gametophyte (embryo sac), consists of an ovule Following fertilization, ovule becomes seed In seed plants, pollen grains are mature sperm-bearing male gametophytes

9. 12 Reduction in the Size of the Gametophyte Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. MossFernGymnospermAngiosperm roots rhizoids seed spores S p o r o p h y t e (2n) G a m e t o p h y t e (n)

10. 15 Nonvascular Plants: Bryophytes Nonvascular plants (bryophytes) Lack specialized means of transporting water and organic nutrients Do not have true roots, stems, and leaves Gametophyte is dominant generation Produces eggs in archegonia Produces flagellated sperm in antheridia Sperm swim to egg in film of water to make zygote

11. 16 Nonvascular Plants Hornworts have small sporophytes that carry on photosynthesis (shown in diagram to the right) Liverworts have either flattened thallus or leafy appearance Mosses usually have a leafy shoot, although some are secondarily flattened Can reproduce asexually by fragmentation Dependent sporophyte consists of foot, stalk, and sporangium sporophyte gametophyte B. Runk/S. Schoenberger/Grant Heilman Photography

12. 12 Alternation of Generations: Nonvascular Plants

13. 20 Vascular Plants Dominate the natural landscape Xylem conducts water and dissolved minerals up from roots Phloem conducts sucrose and other organic compounds throughout the plant Lignin strengthens walls of conducting cells in xylem All seed plants are heterosporous and have male and female gametophytes Seeds disperse offspring

14. Fern Life Cycle

15. 35 Gymnosperms Largest group of gymnosperms = conifers. examples of conifers: pine, spruce, cedar, redwood naked seeds (no fruit) needle like leaves most are evergreens well adapted to hot summers and cold winters

16. Conifer Life Cycle

17. 45 Angiosperms Flowering plants seeds enclosed in fruit “hardwood” trees....maple, oak Two classes of flowering plants Monocotyledones (Monocots) Dicotyledones (Dicots)

18. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Angiosperms – Flowers & Fruits Anther Filament Stigma Style Ovary Carpel Petal Receptacle Ovule Sepal Stamen Peduncle (flower stalk) expands at tip into a receptacle Bears sepals, petals, stamens, and carpels, all attached to receptacle in whorls Calyx (collection of sepals) protect flower bud before it opens Corolla (collection of petals) Each stamen consists of an anther and a filament (stalk) Carpel has three major regions –O–Ovary - Swollen base Fruit –S–Style - Elevates stigma –S–Stigma - Sticky receptor of pollen grains

19. 51 Generalized Flower petals (corolla)sepals (calyx) stamens carpel anther filament stigma ovary ovule style receptacle pollen tube Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

20. Flowering Plant Life Cycle

21. 53 Flowers and Diversification Wind-pollinated flowers are usually not showy Bird-pollinated flowers are often colorful Night-blooming flowers attract nocturnal mammals or insects Usually white or cream-colored Fruits of flowers protect and aid in dispersal Utilize wind, gravity, water, and animals for dispersal

22. 13 Other Terrestrial Adaptations Vascular tissue transports water and nutrients to the body of the plant Cuticle provides an effective barrier to water loss Stomata bordered by guard cells that regulate opening, and thus water loss

23. 14 Leaf Adaptation cuticle a. Stained photomicrograph of a leaf cross section Stomata b. Falsely coloured scanning Electron micrograph of leaf surface 400 x Stomata Plant leaves have a Cuticle and stomata Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (Left): © Kingsley Stern; (Right): © Andrew Syred/SPL /Photo Researchers, Inc.

24. Nonvascular Plants - have small reduced leaves, no vascular tissue(veins to carry water) no true roots, and reproduce by spores or flagellated cells that travel through water. –Bryophyta (mosses) Vascular Plants - have true roots, stems, and leaves with vascular tissue. Xylem- water and minerals. Phloem- transports carbohydrates –seedless plants club moss Ferns –seed plants Gymnosperms - naked seeds –Conifer- needle or scale leaf, cones Angiosperms - flowering plants »Monocots- parallel veins, petals in 3‘s »Dicots- net veins, petals in 4’s or 5’s REVIEW