Exam 4 Study Guide Early Development of the Plant Body What is an embryo Are seed plants the only plants to produce embryos o An embryo is a young sporophyte before the start of a period of rapid growth germination in seed plants o Seed plants are not the only plants to produce embryos i e seedless vascular plant Selaginella How is polarity important in the embryonic development of plants Embryogenesis apical basal pattern radial pattern polarity embryo proper suspensor axis micropylar pole chalazal pole o Establishment of polarity is important to the embryonic development of plants because it fixes the structural axis of the body upon which lateral appendages will be arranged o Embryogenesis Development of an embryo from a fertilized egg or zygote pattern of tissue organization that is vertical i e root o Apical Basal Pattern vertically to shoot o Radial Pattern cross section of the stem o Polarity how the plant axis is set up pattern of tissue organization that is outward growth i e the o Embryo proper will give rise to the tissue systems of the plants o Suspensor a structure at the base of the embryo in many vascular plants line of the body of the plant in which the lateral appendages will be o Axis arranged o Micropylar pole gametophyte o Chalazal pole gametophyte Part of the axis that will turn into the micropyle in the mature part of the axis that will turn into the chalaza in the mature What are the three primary meristems of plants and which tissues do they form Protoderm ground meristem procambium apical meristem primary meristems periclinal division epidermis ground tissue vascular tissue o The three primary meristems of plants are Protoderm Forms the epidermis dermal tissue system Ground Meristem and sclerenchyma ground tissue system Forms the ground tissues parenchyma collenchyma Procambium tissue system Forms the Primary xylem and primary phloem vascular o Apical Meristem The meristem at the tip of the root or shoot in a vascular plant o Primary meristems protoderm procambium and ground meristem tissue derived from the apical meristem of three kinds o Periclinal Division when cell division occurs parallel to the length of the existing the outermost layer of cells of the leaf and young stems and roots cell o Epidermis primary in origin o Ground tissue periderm Also called fundamental tissue Tissue other than the vascular tissues the epidermis and the o Vascular tissue Conducting tissue of water and nutrients xylem and phloem What structures nourish the developing embryo What structures nourish the seedling prior to establishment Suspensor endosperm perisperm cotyledons hilum funiculus o Food reserves flow through the funiculus of the ovule Sources of nourishment to the developing embryo also come from the suspensor endosperm perisperm and cotyledons o Suspensor embryo proper providing nutrients and growth regulators is metabolically active and supports early development of the o Endosperm sporophyte before and or after germination of the seed Is triploid and is unique to angiosperms Nourishes the young food storing tissue derived from the nucellus that occurs in the seeds o Perisperm of some flowering plants o Cotyledons other angiosperms Seed leaf generally absorbs food in monocots and stores food in o Hilum Scar left on a seed after its separation from the funiculus o Funiculus The stalk of the ovule where food reserves flow into the ovule What are the main parts of a mature eudicot embryo A mature monocot embryo Hypocotyl epicotyl plumule radicle hypocotyl root axis scutellum coleorhiza coleoptile o The main parts of a mature eudicot embryo are the hypocotyl epicotyl radicle and plumule the coleoptile o The main parts of a mature monocot embryo are the scutellum coleorhiza and o Hypocotyl attachment of the cotyledons and the radicle the portion of an embryo or seedling situated between the point of o Epicotyl The upper portion of the axis of an embryo or seedling above the point of insertion of the cotyledons and below the next leaf or leaves o Plumule the embryonic shoot which may consist of an epicotyl one or more young leaves and an apical meristem It is above the cotyledons o Radicle The embryonic root o Hypocotyl root Axis cotyledon or cotyledons consisting of the hypocotyl and the apical meristem of the root or radicle Used when the radicle cannot be distinguished in an embryo The embryo axis below the point of attachment of the o Scutellum the endosperm The single cotyledon of a grass embryo specialized for absorption of o Coleorhiza The sheath enclosing the radicle in the grass embryo o Coleoptile grass embryo often interpreted as the first leaf The sheath enclosing the apical meristem and leaf primordial of the What factors affect the timing of seed germination Germination dormancy after ripening o Some factors that affect the timing of seed germination are the maturity of the embryo amount of water amount of oxygen temperature and light o Germination other structure the beginning or resumption of growth by a spore seed bud or o Dormancy a special condition of arrested growth in which the seeds do not begin to grow without special environmental cues The special environmental cues prevent the breakdown of dormancy during superficially favorable growing conditions o After ripening before germination can occur typically triggered by environmental cues metabolic changes that must occur in some dormant seeds How do the steps following germination prior to seedling establishment differ among plants What structure typically emerges first from the seed What alternative strategies are used by plants to protect their apical meristems Primary root tap root lateral roots shoot borne roots hook epigeous germination hypogeous germination o The first structure that typically emerges first from the seed is the root absorbs water and anchors seedling o The steps following germination differ among plants in that they can either undergo epigeous germination or hypogeous germination o Primary Root tip or radicle of the embryo the taproot The first root of the plant developing as a continuation of the root o Taproot The primary root of a plant formed in direct continuation with the root tip or radicle of the embryo forms a stout tapering main root from which arise smaller lateral roots o Lateral roots or secondary roots if the older root is the primary tap root roots that arise from another older root Also called branch roots o Shoot borne roots germination and is replaced
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