Presentation on theme: "Evolution and Diversity of Plants"— Presentation transcript:
1Evolution and Diversity of Plants Mader: Biology 8th Ed.
2Alternation of Generations Nonvascular Plants Vascular Plants Seedless OutlineEvolutionary HistoryAlternation of GenerationsNonvascular PlantsVascular PlantsSeedlessSeedAngiospermsMonocots and DicotsFlowersMader: Biology 8th Ed.
3Evolutionary History of Plants Plants are thought to have evolved from freshwater algae over 500 million years ago.Marked by four evolutionary events associated with four major groups of plants…..Mader: Biology 8th Ed.
4Evolutionary History of Plants Nonvascular Plantsnourishment of a multicellular embryo within the body of the female plant.Seedless Vascular PlantsAdvent of vascular tissue.Gymnosperms and AngiospermsProduce seeds.Flowering PlantsAttract pollinators that give rise to fruits.Mader: Biology 8th Ed.
5Alternation of Generations All plants have a life cycle that includes an alternation of generations.Two multicellular individuals alternate, each producing the other.Sporophyte = diploid generation.Gametophyte = haploid generation.Mader: Biology 8th Ed.
6Alternation of Generations Mader: Biology 8th Ed.
7Alternation of Generations Mader: Biology 8th Ed.
8Alternation 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.
9Reduction in Size of Gametophyte Mader: Biology 8th Ed.
10Alternation 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.
11Protection of Eggs and Embryos Mader: Biology 8th Ed.
12Other Terrestrial Adaptations Vascular tissue transports water and nutrients to the body of the plant.Cuticle is an effective barrier to water loss.Stomata bordered by guard cells that regulate opening, and thus water loss.Mader: Biology 8th Ed.
13Leaves of Vascular Plants Mader: Biology 8th Ed.
14Do not have true roots, stems, or leaves. Nonvascular PlantsDo not have true roots, stems, or 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.
15Nonvascular PlantsHornworts (phylum Anthocerophyta) have small sporophytes that carry on photosynthesis.Mader: Biology 8th Ed.
16Nonvascular PlantsLiverworts (phylum Hepatophyta) have either flattened thallus or leafy appearance.Mader: Biology 8th Ed.
17Can 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.
19Xylem 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.
21Seedless 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.
23Seedless 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.
29Seed 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.
30Gymnosperms (naked seeds) Gymnosperms have ovules andseeds exposed on the surface ofsporophylls.Mader: Biology 8th Ed.
31Conifers, 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.
35Pollen and seed cones on separate plants CycadsCycads (phylum Cycadophyta) have large, finely divided leaves that grow in clusters at the top of the stem. Oldest of the gymnosperms (about 320 million years ago)Pollen and seed cones on separate plantsMader: Biology 8th Ed.
36Ginkgoes (phylum Ginkgophyta) are dioecious (male and female plants) with some trees producing seeds and others producing pollen.One surviving species =Gingko bilobaMader: Biology 8th Ed.
37Gnetophytes (phylum Gnetophyta) believed to be closest to angiosperms because of similarity in xylem tissue and some even produce nectar for pollinators!Mader: Biology 8th Ed.
38Angiosperms (covered seeds) Angiosperms (phylum Anthophyta)are an exceptionally large and successful group of plants.Produce flowersSeeds are enclosed in a fruit.Oldest fossils are 130 million years oldMader: Biology 8th Ed.
39Two 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.
40Penducle (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.
41Each 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.
43Flowering Plant Life Cycle Mader: Biology 8th Ed.
44Flowering Plant Life Cycle Mader: Biology 8th Ed.
45Flowers 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.