2006-2007学年第1学期 试题名称 ：植物生物学A卷1. Please give definition of the following botanical terms (40 points, 4 points each one)1.1 Endomembrane system Collectively, the cellular membranes that form a continuum (plasma membrane, tonoplast, endoplasmic reticulum, Golgi bodies, and nuclear envelope).1.2 Crossing over The exchange of corresponding segments of genetic material between the chromatids of homologous chromosomes at meiosis.1.3 Casparian strip A bandlike region of primary wall containing suberin and lignin; found in anticlinal-radial and transverse-walls of endodermal and exodermal cells. 1.4 Sporic meiosis Meiosis resulting in the formation of haploid spores by a diploid individual, or sporophyte ; the spores give rise to haploid individuals, or gametophytes, which eventually produce gametes that fuse to form diploid zygote; the zygotes, in turn, develop into sporophytes; this kind of life cycle is known as an alternation of generations. 1.5 Basidiospores Spores of the basidiomycota, produced within and borne on a basidium following nuclear fusion and meiosis. 1.6 Type specimen Usually a dried plant specimen housed in an herbarium; selected by a taxonomist to serve as the basis for comparison with other specimens in determining whether they are members of the same species or not. 1.7 Unilocular sporangium The unilocular reproductive structure which were produced by diploid sporophytes to form haploid zoospores that germinate to produce gametophytes, meiosis firstly takes place within the unilocular sporangia. 1.8 Sorus A group or cluster of sporangia or spores in ferns.1.9 Ovuliferous scales In certain conifers, the appendage or scalelike shoot to which the ovule attached.1.10 arietal placentation Of placentation, with placentas positioned on the wall of a unilocular compound ovary and ovules attached to the outer wall of the ovary instead of the axis and pointing inwards.2.Questions (60 points)1） What is meant by the cell theory, and what three features of plant cells distinguish them from animal cells? (10 points)In its modern form, the cell theory states that (1) all living organisms are composed of one or more cells; (2) the chemical reactions of a living organism, including its energy-releasing processes and its biosynthetic reactions, take place within cells; (3) cell arise from other cells; and(4) cells contain the hereditary information of the organisms of which they are a part, and this information is passed from parent cell to daughter cell.In contrast to animal cells, plant cells have vacuoles, cell walls, and plastids.2)What is tissue system? In ground tissue system, How many tissues and cell types are included? Please summarize their characteristics, location and function respectively. (10 points)Tissue system: A tissue or group of tissues organized into a structural and functional unit in a plant or plant organ. There are three tissue systems: dermal, vascular, and ground or fundamental.Three type of tissues are included in ground tissue system, parenchyma tissue, collenchyma tissue and sclerenchyma tissue.Parenchyma tissue is composed of only one type of cell, parenchyma cell.Characteristics: commonly polyhedral(many-sided); variable.Cell wall: primary, or primary and secondary; may be lignified, suberized or Cutinized; living at maturity.Location: throughout the plant, as parenchyma tissue in cortex; as pith and pith rays; in xylem and phloem.Function: such metabolic process as respiration, digestion, and photosynthesis; storage and conduction; wound healing and regeneration.Collenchyma tissue is also composed of only one type of cell, collenchyma cell.Characteristics: elongated; cell wall: unevenly thickened, primary only-nonlignified; living at maturity.Location: on the periphery(beneath the epidermis) in young elongating stems, often as a cylinder of tissue or only in patches; in ribs along veins in some leaves.Function: support in primary plant body.Sclerenchyma tissue is composed of two types of cell: fiber and sclereid.Fiber Characteristics: shape generally very long; cell wall: primary and thick secondary often lignified; living at maturity.Location: sometimes in cortex of stems, most often associated with xylem and phloem; in leaves of monocotyledons.Function: support; storage.Sclereid Characteristics: shape variable; generally shorter than fibers; cell wall: primary and thick secondary-generally lignified; may be living or dead at maturity.Location: throughout the plant.Function: mechanical and protective.3) Please summarize stem development in a woody angiosperm during the first year of growth. (10 points)Summary of stem development in a woody angiosperm during the first year of growth.4) Porphyra sp. is an important seaweed for cultivation, please describe its life Cycle in detail. (10 points) Life cycle of Porphyra sp.-Alternation of heteromorphic generati