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On-Line Glossary: B

Each entry consists of a term (in bold), a definition of the term, and a number in parentheses (0) indicating the source of the definition. Clicking on the speaker icon will give you the pronunciation of the term. (Be sure to close the window for the sound player after each use.) The pencil icon will give you a drawing, and the camera icon will give you a photograph.


bacillar. Shaped like a short rod. (21)

bacilliform. Rod-shaped. (17)

bacillus. 1. A member of the genus Bacillus. 2. Any rod-shaped bacterial cell, i.e., a cell whose length is ca. two or more times greater than its width. (16)

backcross. To cross (mate) with one parent. (13)

bactericidal. Lethal to bacteria. (20)

bactericide. A substance that kills bacteria. (8)

bacteriocin. A protein antibiotic, one or more types of which can be produced and "exported" (excreted) by certain strains of bacteria. (16)

bacteriophage. A virus that replicates inside a bacterium. (10)

bacteriostatic. Able to inhibit the growth and reproduction of at least some types of bacteria. (16)

ballistospore. A spore that when mature is actively projected. (17)

basidiocarp. A sporocarp produced by a member of the Basidiomycotina and which bears basidiospores. (15)

basidiole. A structure in the hymenium of a member of the Basidiomycotina that is morphologically similar to a basidium without sterigmata. It may be an immature basidium or a permanently sterile structure in the hymenium. (15)

basidioma. See basidiocarp. (pl. basidiomata.) (7)

basidiomycete. A fungus of the Basidiomycotina. (16)

Basidiomycetes. See Basidiomycotina.

Basidiomycota. See Basidiomycotina.

Basidiomycotina. A subdivision of fungi characterized by the formation of basidiospores on basidia. , (16)

basidiospore. An exogenous sexual spore (meiospore) borne on a basidium. (15)

basidium. A cell in which karyogamy and meiosis take place and which bears exogenous spores of sexual origin. (Pl. basidia.) (15)

basipetal. Successive from apex to base. (20)

bifurcate. Dividing into two branches. (14)

binary fission. Fission in which two cells, usually of similar size and shape, are formed by the growth and division of one cell. (16)

bioassay. Any quantitative procedure in which a given organism is used for assay purposes. (16)

biocontrol. See biological control.

biological control. The deliberate use by humans of one species of organism to eliminate or control another. (1)

biotroph. An organism that derives nutrients from the living tissues of another organism (its host). (16)

biotype. A subspecies of organism morphologically similar to but physiologically different from other members of the species. (5)

bipolar. At both ends or poles. (17)

biseptate. Having two septa. (17)

bitunicate. Having two walls.

blastic. One of two basic kinds of conidiogenesis; there is a marked enlargement of a recognizable conidium before it is delimited by a septum. (See thallic.) (23)

blasting. A symptom of plant disease characterized by shedding of unopened buds; classically, the failure to produce fruit or seed. (20)

blastoconidium. See blastospore.

blastospore. A spore that arises by budding, as in yeasts. (17)

blight. A disease characterized by rapid and extensive death of plant foliage. A general term applied to any of a wide range of unrelated plant diseases. (e.g., chestnut blight, fireblight, late blight, halo blight) (5) (16)

blot. See blotting.

blotch. A disease characterized by large, and irregular in shape, spots or blots on leaves, shoots, and stems. (2)

blotting. Following electrophoresis: the transfer of nucleic acids and/or proteins from a gel strip to a specialized, chemically reactive matrix on which the nucleic acids, etc. may become covalently bound in a pattern similar to that present in the original gel. (16)

broadcast application. Application by spreading or scattering on the soil surface. (5)

broom. In plant pathology: A symptom in which lateral branches proliferate in a dense cluster on the main branch (witches'-broom). (21)

broth. In microbiology: Any of a variety of liquid media, especially nutrient broth or any liquid medium based on nutrient broth and/or hydrolysed protein. (16)

buccal capsule. In nematodes: Structure connecting the oral opening with the anterior portion of the esophagus. The buccal capsule (also called the stoma) is subject to great variation among different nematodes. (14)

bullae. In nematodes: Blisterlike prominences near the vulval fenestra of some Heteroderidae. (14)

bursa. In nematodes: Caudal alae of males used to clasp the female during copulation. (14)

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