The Facts On File Dictionary of Botany is planned as an additional source of information for students taking Ad- vanced Placement (AP) Science courses in high schools, but will also be helpful to older students taking introductory college courses. This volume covers the whole area of pure and applied plant science including anatomy and plant morphology, plant physiology, biochemistry, cell biology, genetics, evolution, and ecology. It also covers the taxonomy and classification of plants, with entries for the higher-ranking taxa. The definitions are intended to be clear and informative and, where possible, we have provided helpful diagrams and examples. The book also has a selection of short biographical entries for people who have made important contributions to the field. The appendices include lists of webpages and an informative bibliography. The book will be a helpful additional source of information for anyone studying AP Biology, notably the sections on Organisms and Populations, Structure and Function of Plants and Animals, and Molecules and Cells. However, we have not restricted the content to this syllabus. Modern plant science is a subject of considerable importance and we hope that this book will be useful to anyone interested in the subject.
[...]... are separated aneuspory The production of an unusual number of spores during meiosis of a spore mother cell In dandelion (Taraxacum), for example, the chromosomes of the megaspore mother cell remain in one cell after the first meiotic division, forming a restitution nucleus The second meiotic division thus gives rise to two cells with the diploid number of chromosomes, one of which divides parthogenetically... represented by the embryo sac, the archegonia being absent The contents of the pollen grain represent the male gametophyte The pollen grain germinates on a special extension of the carpel, the stigma, and double fertilization results in a diploid zygote and triploid (usually) endosperm nucleus Angiosperms are divided into two major classes, the monocotyledons (MONOCOTYLEDONAE) and dicotyledons (DICOTYLEDONAE),... staining anion A negatively charged ion, formed by addition of electrons to atoms or molecules In electrolysis anions are attracted to the positive electrode (the anode) Compare cation anisogamy (heterogamy) The sexual fusion of nonidentical gametes Anisogamy grades from situations in which the gametes differ only in size to the extreme of oogamy, in which one gamete is a large nonmotile ovum and the other... production air bladder 1 A structure on the pollen grains of some conifers, such as Pinus, that aids the wind dispersal of the pollen It consists of an air-filled protuberance on each side of the pollen grain developed by the separation of the exine layers, giving the pollen a characteristic winged appearance 2 An air-filled chamber in the thallus of many Phaeophyta (brown algae) that increases the buoyancy... is a form of APOMIXIS Since crossing over can occur during the first meiotic division, it does allow for some genetic variation in the offspring See parthenogenesis anatomy The organization of the parts of the body and the structural relationships between them, including the arrangement of tissues and their component cells anatropous See ovule androdioecious Describing species in angiosperms The flowering... bacteria Alcoholic fermentation is catalyzed by enzymes of the zymase complex, which are secreted by the cells or released after the cells die The process is self-limiting, since the organisms usually die once the alcohol concentration in the medium exceeds 15% Alcoholic fermentation is the basis of the preparation of alcoholic beverages, and of bread making (in which the carbon dioxide air plant See epiphyte... 10–10 meter (one thousandth of a micrometer, one tenth of a nanometer) It is still used occasionally for measurements of wavelength or interatomic distance annulus 1 The ring of tissue surrounding the stalk of the mature fruiting body (mushroom or toadstool) of the basidiomycete fungi The annulus is all that remains of the veil, which joined the rim of the pileus (cap) to the stalk in the immature... sometimes termed the velum 2 A special arc or ring of cells in the sporangia of ferns that constitutes the mechanism for spore dispersal The cells of the annulus are thickened except on the outer wall, so that they contract on drying out This causes the stomium to rupture, exposing the spores within the capsule The capsule wall gradually bends back as the water in the annulus cells continues to evaporate... water, and with the sole exception of the simplest member, glycine, all are optically active Amino acids are the basic components of proteins, which consist of chains of amino acids Plants also contain some 200 in which there is only one leaf at each node, as in hazel This is the commonest form of leaf arrangement See phyllotaxis alternate host Any host other than the main (most common) one For example,... found in the embryo sac of seed-bearing plants that migrate to the chalazal end of the sac farthest from the micropyle These nuclei arise as a result of the three meiotic divisions that produce the egg cell, synergid cells, and polar nuclei, but they do not themselves take part in the fertilization process They are eventually absorbed by the developing embryo, and their function is uncertain They do . class="bi x0 y0 w0 h0" alt="" The Facts On File DICTIONARY of BOTANY The Facts On File DICTIONARY of BOTANY Edited by Jill Bailey The Facts On File Dictionary of Botany Copyright © 2003 by Market. dictionary is one of a series covering the terminology and concepts used in important branches of science. The Facts On File Dictionary of Botany is planned as an additional source of information. pro- duction. air bladder 1. A structure on the pollen grains of some conifers, such as Pinus, that aids the wind dispersal of the pollen. It consists of an air-filled protuberance on each side of the