The Facts On File Dictionary of Botany

aniline stainsbacteria and lactic acid bacteria. Compareaerobe.anaerobic respiration Respiration inwhich oxygen is not involved, found in almostall organisms. The organic substrateis not completely oxidized and the energyyield is low. The glycolytic pathway,whereby glucose is degraded to pyruvate,with the production of a small amount ofenergy, is the same as in aerobic respiration,but after that, in plants and fungi,ethanol and carbon dioxide are producedas the end products of the process, normallyknown as FERMENTATION. In animalslactic acid is produced and normally remetabolizedwith oxygen at a later stage. Onlytwo molecules of ATP are produced by thisprocess. See anaerobe; glycolysis. Compareaerobic respiration.analogous Describing structures thatare apparently similar (structurally orfunctionally) but have a different evolutionaryorigin, and thus a different embryologicalorigin and structure. Phyllodes areanalogous to leaf blades, but are derivedfrom petioles (leaf stalks). See also homologous.anaphase The stage in mitosis or meiosiswhen chromatids are pulled toward oppositepoles of the nuclear spindle. Inmitosis each of the chromatids moving towardthe poles represents a single completechromosome. During anaphase I of meiosispairs of chromatids still connected at theircentromere move to the spindle poles. Duringanaphase II the centromeres divide andsingle chromatids are drawn toward thepoles, thus sister chromatids are separated.anatomy The organization of the partsof the body and the structural relationshipsbetween them, including the arrangementof tissues and their component cells.anatropousSee ovule.androdioecious Describing species inwhich there are two forms, one bearingonly male flowers, the other bearing onlyhermaphrodite flowers (or occasionallybearing male and female flowers, i.e. MO-NOECIOUS). Compare gynodioecious.androecium The collective name inhigher plants for the male parts of a plant,i.e. the STAMENS. It is denoted in the floralformula by a letter A.andromonoecious Describing speciesin which both male and hermaphroditeflowers are borne on the same plant. Comparegynomonoecious.anemophily Pollination by wind. Plantspollinated in this manner (e.g. grasses) usuallyhave insignificant unscented flowerswith large, often feathery stigmas.aneuploidy The condition, resultingfrom nondisjunction of homologous chromosomesat meiosis, in which one or morechromosomes are missing from or added tothe normal somatic chromosome number.If both of a pair of homologous chromosomesare missing, nullisomy results. Monosomyand trisomy are the conditions inwhich one or three homologs occur respectively,instead of the normal two. Polysomy,which includes trisomy, is thecondition in which one or more chromosomesare represented more than twice inthe cell. See nondisjunction.aneuspory The production of an unusualnumber of spores during meiosis of aspore mother cell. In dandelion (Taraxacum),for example, the chromosomes ofthe megaspore mother cell remain in onecell after the first meiotic division, forminga restitution nucleus. The second meioticdivision thus gives rise to two cells with thediploid number of chromosomes, one ofwhich divides parthogenetically to form anembryo. This is a form of APOMIXIS. Sincecrossing over can occur during the firstmeiotic division, it does allow for some geneticvariation in the offspring. See parthenogenesis.angiosperms The flowering plants constitutingby far the largest phylum (Antho-15