Plant Biology PDF

Plants: 26.3, 26.4, and 28.1: Visual: vascular tissue: cells joined into tubes that transport water and nutrients throughout the plant body. Vascular plants: plants that have a complex vascular tissue system ○ Seedless Vascular Plants: lycophytes (club mosses and...

Plants: 26.3, 26.4, and 28.1: Visual: vascular tissue: cells joined into tubes that transport water and nutrients throughout the plant body. Vascular plants: plants that have a complex vascular tissue system ○ Seedless Vascular Plants: lycophytes (club mosses and their relatives) monilophytes (ferns and their relatives). The nonvascular plants (bryophytes): small herbaceous (nonwoody) plants: Liverworts mosses Hornworts Xylem and Phloem: Two main types of vascular tissue conducts most of the water and minerals ○ tracheids: tube-shaped cells that carry water and minerals up from the roots ○ Lignin: polymer that strengthens cells walls of water-conducting cells enable vascular plants to grow tall, giving them advantage in terms of access to sunlight and spore distribution ○ Phloem: has cells arranged into tubes that distribute sugars, amino acids, and other organic products Roots and Leaves: Roots: organs that absorb water and nutrients from the soil and anchor vascular plants Leaves: serve as the primary photosynthetic organ of vascular plants. ○ Microphylls: small, usually spine-shaped leaves supported by a single strand of vascular tissue. Only grow in lycophytes ○ Megaphylls: leaves with a highly branched vascular system Gymnosperms and Angiosperms: Seed: consists of an embryo and its food supply, surrounded by a protective coat. ○ Gymnosperms: seeds that are not protected by plant ○ Angiosperms: developed and protected inside ovaries Angiosperms:  Stamens produce pollen grains containing male gametophytes ○ Anther: produce pollen ○ Filaments: provides structure to anther Carpels: make ovules, which, as in gymnosperms, contain female gametophytes. ○ Stigma: collects pollen ○ Style: contains pollen tube ○ Ovary: contains ovules Roots: ○ Taproot: one thick primary root of dicots ○ Fibrous roots: many thin roots of monocots ○ Adventitious Roots: grow from above ground parts ○ Root Hairs: increase surface area of mineral and water absorption Stems: organ to which leaves are attached ○ Nodes: where leaves are attached ○ Internodes: stem segments between nodes ○ Apical Bud: most growth that occurs near shoot tip ○ Axillary buds: could form vegetative branches Leaves: ○ Blade: flat surface ○ Petiole: joins leaf stem to node Tissue Systems: ○ Dermal: outer protection Consists of epidermis for nonvasc plants Cuticle: waxy coating on the epidermal surface, helps prevent water loss. In woody plants, protective tissues called periderm ○ Ground Tissue: Storage, metabolism, support for all three types of plants ○ Vascular tissue: xylem and phloem Types of Plant Cells: ○ Parenchyma: metabolic functions ○ Collenchyma: support parts of plants still lengthening  ○ Sclerenchyma: support plants where growth is NOT occurring 28.2-28.4: Growth: Apical Meristems: provide additional cells that enable growth in length, aka primary growth Secondary growth: growth in thickness by lateral meristems vascular cambium adds layers of vascular tissue called secondary xylem (wood) and secondary phloem. The cork cambium replaces the epidermis with the thicker, tougher periderm. Growth in Roots: Root cap: covers tip of the root Primary Growth of Shoots: ○ Leaves develop from leaf primordia ○ Branching, which is also part of primary growth, arises from  ○ the activation of axillary buds. Within each axillary bud is a shoot apical meristem. Its dormancy results from inhibition by an active apical bud, a phenomenon called apical dominance. Tissue organization in leaves: ○ Stomata: pores that allow an exchange of CO2 and O2 between the surrounding air and the photosynthetic cells inside the leaf. Guard cells: regulate opening and closing of pores ○ Mesophyll: ground tissue of a leaf, ○ Bundle sheat: bundle of cells that regulate movement of substances between vascular tissue and mesophyll Secondary Growth in diameter of stems and roots: ○ vascular cambium: a cylinder of meristematic cells only one cell thick, is wholly responsible for the production of secondary vascular tissue. Makes secondary xylem (wood) and secondary phloem ○ Cork cambium: Produces waxy cells that prevent water loss  Asexual Plant Propagation: Method to which identical clones are produced by a single parent Plant tissue culture (PTC): growing small pieces of plants on sterile culture medium ○ Meristematic tissue must be present since meristematic cells are responsible for growth Explants: pieces of plants used to grow in PTC Know methods to PTC based on labs Hormones: Auxin: responsible for cell elongation and leaf development Cytokinin: regulates cell division Ethylene: regulates fruit ripening and leaf development Gibberellin: regulates seed germination, leaf bud germination, and stem elongation Abscisic Acid (ABA): regulates bud development and seed dormancy Phytochrome: pigment that acts like a hormone to control flowering