Term
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Definition
| a gelatinous substance produced by certain red algae and also a few brown algae; it is often used as a culture medium, particularly for bacteria |
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| Aggregation (Dictyosteliomycota) |
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Definition
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Definition
| a gelatinous substance produced by certain brown algae; it is used in a wide variety of food substances and in pharmaceutical, industrial, and household products |
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Term
| alternation of generations |
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Definition
| alternation between a haploid gametophyte phase and a diploid sporophyte phase in the life cycle of sexually reproducing organisms |
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Definition
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Definition
| a specialized layer of cells around a fern sporangium; it aids in spore dispersal through a springlike action; also a membranous ring around the stipe of a mushroom |
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Definition
| the male gametangium of certain algae, fungi, bryophytes, and vascular plants other than gymnosperms and angiosperms |
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Term
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Definition
| one of often numerous, frequently fingerlike hollow structures in which the fusion of two haploid nuclei is followed by meiosis; a row of ascospores (usually 8) is ultimately produced in each ascus on or within the sexually initiated reproductive bodies of cup (sac) fungi |
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Term
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Definition
| one of usually numerous, frequently club-shaped hollow structures in which the fusion of two haploid nuclei is followed by meiosis, the four resulting nuclei becoming externally borne basidiospores; basidia are produced on or within sexually initiated reproductive bodies of the club fungi |
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Term
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Definition
| a meristem producing secondary tissues |
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Term
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Definition
| an organelle containing chlorophyll, found in cells of most photosynthetic organisms |
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Term
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Definition
| multinucleate, the nuclei not individually separated from one another by crosswalls, as in the hyphae of water molds |
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Term
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Definition
| tissue composed of cells with unevenly thickened walls |
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Definition
| an asecually produced fungal spore formed outside of a sporangium |
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Definition
| a waxy or fatty layer of varying thickness on the outer walls of epidermal cells |
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Term
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Definition
| having two sets of chromosomes in each cell; the 2n chromosome number characteristic of the sporophyte generation |
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Definition
| the exterior tissue, usually one cell thick, of leaves, young stems and roots, and other parts of plants |
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Term
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Definition
| a fine, threadlike structure protruding from a motile unicellular organism or the motile cells produced by multicellular organisms; functions primarliy in locomotion |
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Definition
| any cell structure in which gametes are produced |
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Term
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Definition
| a sex cell; one of two cells that unite, forming a zygote |
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Definition
| a series of stacked thylakoids within a chloroplast |
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Term
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Definition
| having one set of chromosomes per cell, as in gametophytes; also referred to as having n chromosomes |
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Term
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Definition
| a collection of dried, pressed specimens, usually mounted on paper and provided with a label that gives collection information and an identification |
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Term
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Definition
| the process of two successive nuclear divisions through which segregation of genes occurs and a single diploid cell becomes four haploid cells |
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Definition
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Definition
| a symbiotic association between fungal hyphae and a plant root |
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Definition
| a female sex organ of certain algae and fungi; it consists of a single cell that contains one to several eggs |
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Definition
| thin-walled cells varying in size, shape, and function; the most common type of plant cell |
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Definition
| the food-conducting tissue of a vascular plant |
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Term
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Definition
| the equivalent of a conjugation tube in bacteria |
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Definition
| minute stands of cytoplasm that extend between adjacent cells through pores in the walls |
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Term
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Definition
| the multinucleate, semiviscous liquid, active form of slime mold; it moves in a "crawling-flowing" motion |
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Definition
| an organelle associated primarily with the storage or manufacture of carbohydrates |
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Term
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Definition
| an organism that obtains its food directly from nonliving organic matter |
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Definition
| tissue composed of lignified cells with thick walls; the tissue functions primarily in strengthening and support |
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Term
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Definition
| a single cell of a sieve tube |
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Term
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Definition
| a column of sieve tube members arranged end to end; food is conducted from cell to cell through sieve plates |
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Definition
| an area of the wall of a sieve tube member that contains several to many perforations that permit cytoplasmic connection between similar adjacent cells, the cytoplasmic strands being larger than the plasmodesmata |
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Definition
| a structure in which spores are produced; it may be either unicellular or multicellular |
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Definition
| the supporting stalk of seaweeds, mushrooms, and certain other stationary organisms |
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Term
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Definition
| a minute pore or opening in the epidermis of leaves, herbaceous stems, and the sporophytes of hornworts; it is flanked by two guard cells that regulate its opening and closing and thus regulate gas exchange and transpiration |
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Term
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Definition
| a region constituting the bulk of the volume of a chloroplast or other plastid; it contains enzymes that in chloroplasts play a key role in carbon fixation, carbohydrate synthesis, and other photosynthetic reactions |
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Term
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Definition
| an intimate association between two dissimilar organisms that benefits both of them (mutualism) or is harmful to one of them (parasitism) |
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Term
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Definition
| a multicellular plant body that is usually flattened and not organized into roots, stems or leaves |
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Term
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Definition
| coin-shaped membranes whose contents include chlorophyll; they are arranged in stacks that form the grana of chloroplasts |
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Term
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Definition
| an aggregation of cells having a common function |
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Term
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Definition
| a xylem cell that is tapered at the ends and has thick walls containing pits |
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Term
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Definition
| a pocket of fluid that is separated from the cytoplasm of a cell by a membrane; it may occupy more than 99% of a cell's volume in plants; also, food-storage or contractile pockets within the cytoplasm of unicellular organisms |
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Term
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Definition
| a single cell of a vessel |
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Term
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Definition
| one of usually very numerous cylindrical "tubes" whose cells have lost their cytoplasm; occur in the xylem of most angiosperms and a few other vascular plants; each vessel is composed of vessel members laid end to end; the perforated or open-ended walls of the vessel members permit water to pass through freely |
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Term
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Definition
| the tissue through which most of the water and dissolved minerals utilized by a plant are conducted; it consists of several types of cells |
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Definition
| a motile spore occurring in algae and fungi |
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Definition
| the product of the union of two gametes |
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