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 o Seed plants are not the only plants to produce embryos i e seedless vascular plant germination in seed plants 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 o Radial Pattern pattern of tissue organization that is vertical i e root vertically to o Embryogenesis o Apical Basal Pattern Development of an embryo from a fertilized egg or zygote pattern of tissue organization that is outward growth i e the cross it fixes the structural axis of the body upon which lateral appendages will be arranged shoot section of the stem gametophyte o Chalazal pole gametophyte o Polarity o Embryo proper o Suspensor o Axis o Micropylar pole line of the body of the plant in which the lateral appendages will be arranged a structure at the base of the embryo in many vascular plants 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 will give rise to the tissue systems of the plants how the plant axis is set up 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 Ground Meristem Protoderm sclerenchyma ground tissue system Procambium system o Apical Meristem o Primary meristems procambium and ground meristem o Periclinal Division Forms the epidermis dermal tissue system Forms the ground tissues parenchyma collenchyma and Forms the Primary xylem and primary phloem vascular tissue The meristem at the tip of the root or shoot in a vascular plant tissue derived from the apical meristem of three kinds protoderm when cell division occurs parallel to the length of the existing cell the outermost layer of cells of the leaf and young stems and roots primary Tissue other than the vascular tissues the epidermis and the periderm o Epidermis o Ground tissue in origin Also called fundamental tissue 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 o Endosperm Is triploid and is unique to angiosperms Nourishes the young sporophyte is metabolically active and supports early development of the embryo developing embryo also come from the suspensor endosperm perisperm and cotyledons o Suspensor proper providing nutrients and growth regulators before and or after germination of the seed some flowering plants o Cotyledons angiosperms The stalk of the ovule where food reserves flow into the ovule Scar left on a seed after its separation from the funiculus food storing tissue derived from the nucellus that occurs in the seeds of Seed leaf generally absorbs food in monocots and stores food in other o Hilum o Funiculus o Perisperm 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 o The main parts of a mature monocot embryo are the scutellum coleorhiza and the o Epicotyl o Plumule The embryonic root o Radicle o Hypocotyl root Axis the portion of an embryo or seedling situated between the point of The upper portion of the axis of an embryo or seedling above the point of the embryonic shoot which may consist of an epicotyl one or more young coleoptile o Hypocotyl attachment of the cotyledons and the radicle insertion of the cotyledons and below the next leaf or leaves leaves and an apical meristem It is above the cotyledons 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 o Scutellum endosperm o Coleorhiza o Coleoptile embryo often interpreted as the first leaf The sheath enclosing the radicle in the grass embryo The sheath enclosing the apical meristem and leaf primordial of the grass The single cotyledon of a grass embryo specialized for absorption of the The embryo axis below the point of attachment of the cotyledon 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 o Germination the beginning or resumption of growth by a spore seed bud or other amount of water amount of oxygen temperature and light structure o Dormancy grow without special environmental cues The special environmental cues prevent the breakdown of dormancy during superficially favorable growing conditions germination can occur typically triggered by environmental cues a special condition of arrested growth in which the seeds do not begin to metabolic changes that must occur in some dormant seeds before o After ripening 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 o Taproot o Primary Root The first root of the plant developing as a continuation of the root tip or The primary root of a plant formed in direct continuation with the root tip or epigeous germination or hypogeous germination radicle of the embryo the taproot radicle of the embryo forms a stout tapering main root from which arise smaller lateral roots o Lateral roots secondary roots if the older root is the primary tap root and is replaced by these shoot borne roots straightens o Epigeous germination o Hypogeous germination occurs when the
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