Presentation on theme: "Evolution and Diversity of Plants"— Presentation transcript:
1 Evolution and Diversity of Plants Chapter 24Mader: Biology 8th Ed.
2 Alternation of Generations Nonvascular Plants Vascular Plants Seedless OutlineEvolutionary HistoryAlternation of GenerationsNonvascular PlantsVascular PlantsSeedlessSeedAngiospermsMonocots and EudicotsFlowersMader: Biology 8th Ed.
3 Evolutionary History of Plants Plants are thought to have evolved from freshwater algae over 500 mya.Evolution of plants marked by four evolutionary events associated with four major groups of plants.Nonvascular PlantsAdvent of nourishment of a multicellular embryo within the body of the female plant.Mader: Biology 8th Ed.
4 Evolutionary History of Plants Seedless vascular plantsAdvent of vascular tissue.Gymnosperms and angiospermsProduce seeds.Flowering PlantsAttract pollinators that give rise to fruits.Mader: Biology 8th Ed.
6 Alternation of Generations All plants have a life cycle that includes an alternation of generations.Two multicellular individuals alternate, each producing the other.Sporophyte represents diploid generation.Gametophyte represents haploid generation.Mader: Biology 8th Ed.
7 Alternation of Generations Mader: Biology 8th Ed.
8 Alternation of Generations Mader: Biology 8th Ed.
9 Alternation of Generations Sporophyte (2n) is named for its production of spores by meiosis.Spore is haploid reproductive cell.Gametophyte (n) is named for its production of gametes.Mader: Biology 8th Ed.
10 Reduction in Size of Gametophyte Mader: Biology 8th Ed.
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.Mader: Biology 8th Ed.
12 Protection of Eggs and Embryos Mader: Biology 8th Ed.
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.Mader: Biology 8th Ed.
14 Leaves of Vascular Plants Mader: Biology 8th Ed.
15 Do not have true roots, stems, and leaves. Nonvascular PlantsNonvascular 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 and flagellated sperm in antheridia.Sperm swim to egg in film of water.Mader: Biology 8th Ed.
16 Nonvascular PlantsHornworts (phlym Anthocerophyta) have small sporophytes that carry on photosynthesis.Mader: Biology 8th Ed.
17 Nonvascular PlantsLiverworts (phylum Hepatophyta) have either flattened thallus or leafy appearance.Mader: Biology 8th Ed.
18 Can reproduce asexually by fragmentation. Nonvascular PlantsMosses (phylum Bryophyta) usually have a leafy shoot, although some are secondarily flattened.Can reproduce asexually by fragmentation.Dependent sporophyte consists of foot, stalk, and sporangium.Mader: Biology 8th Ed.
20 Xylem conducts water and dissolved minerals up from roots. Vascular PlantsXylem 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.Mader: Biology 8th Ed.
22 Most seedless vascular plants are homosporous. Windblown spores are dispersal agents.All seed plants are heterosporous and have male and female gametophytes.Seeds disperse offspring.Mader: Biology 8th Ed.
23 Seedless Vascular Plants Club Mosses (phylum Lycophyta)Typically, branching rhizome sends up short aerial stems.Leaves are microphylls (have only one strand of vascular tissue).Sporangia occur on surfaces of sporophylls.Grouped into club-shaped strobili.Mader: Biology 8th Ed.
25 Seedless Vascular Plants Ferns and AlliesHorsetails (phylum Sphenophyta)Rhizome produces tall aerial stems.Contains whorls of slender, green branches.Small, scalelike leaves also form whorls at the joints.Mader: Biology 8th Ed.
31 Seed plants are the most plentiful plants in the biosphere. Seed coat and stored food allow an embryo to survive harsh conditions during long period of dormancy.HeterosporousDrought-resistant pollen grains.Ovule develops into seed.Mader: Biology 8th Ed.
32 GymnospermsGymnosperms have ovules and seeds exposed on the surface of sporophylls.ConfiersCycadsGinkgoesGnetophytesMader: Biology 8th Ed.
33 Conifers, as well as other gymnosperm phyla, bear cones. Tough, needlelike leaves of pines conserve water with a thick cuticle and recessed stomata.Considered a “soft” wood because it consists primarily of xylem tissue.Mader: Biology 8th Ed.
37 Pollen and seed cones on separate plants. Pollinated by insects. CycadsCycads (phylum Cycadophyta) have large, finely divided leaves that grow in clusters at the top of the stem.Pollen and seed cones on separate plants.Pollinated by insects.Mader: Biology 8th Ed.
38 One surviving species. (Gingko biloba) GinkgoesGinkgoes (phylum Ginkgophyta) are dioecious, with some trees producing seeds and others producing pollen.One surviving species. (Gingko biloba)Mader: Biology 8th Ed.
39 GnetophytesGnetophytes (phylum Gnetophyta) have similarly structured xylem, while none have archegonia, but strobili have similar construction.Mader: Biology 8th Ed.
40 Ovules are always enclosed within diploid tissues. AngiospermsAngiosperms (phylum Anthophyta) are an exceptionally large and successful group of plants.Ovules are always enclosed within diploid tissues.Became dominant group of plants in the late Cretaceous and early Paleogene periods.Mader: Biology 8th Ed.
41 Two classes of flowering plants. Monocotyledones (Monocots) Monocots and EudicotsTwo classes of flowering plants.Monocotyledones (Monocots)One cotyledon in seed.Eudicotyledones (Dicots)Two cotyledons in seed.Mader: Biology 8th Ed.
42 Penducle (flower stalk) expands at tip into a receptacle. The FlowerPenducle (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).Mader: Biology 8th Ed.
43 Each stamen consists of an anther and a filament (stalk). The FlowerEach stamen consists of an anther and a filament (stalk).Carpel has three major regions.Ovary - Swollen base.FruitStyle - Elevates stigma.Stigma - Sticky receptor of pollen grains.Mader: Biology 8th Ed.
45 Flowering Plant Life Cycle Mader: Biology 8th Ed.
46 Flowering Plant Life Cycle Mader: Biology 8th Ed.
47 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.Mader: Biology 8th Ed.
48 Alternation of Generations Nonvascular Plants Vascular Plants Seedless ReviewEvolutionary HistoryAlternation of GenerationsNonvascular PlantsVascular PlantsSeedlessSeedAngiospermsMonocots and EudicotsFlowersMader: Biology 8th Ed.