See also animals; botany; cells; life; organisms; plants; zoology.abiogenesis
the process of generation of living organisms from inanimate matter; spontaneous generation. —abiogenetic, adj.
asexual reproduction. —agamogenetic, adj.agrobiology
the branch of biology that studies the relation of soil management to the nutrition, growth, and erop yield of plants. —agrobiologist, n.
—agrobiologic, agrobiological, adj.amensalism
the living together of two organisms in a relationship that is destructive to one and has no effect on the other.anamorphism
gradual change in type, usually from a lower to a higher type. Also anamorphosis
, (Obsolete) anamorphosy
. —anamorphic, adj.anastomosis
connection between parts that have branched off from each other at some earlier point. —anastomotic, adj.anisogamy
a form of reproduction in which dissimilar gametes, often dirfering in size, unite. —anisogamous, anisogamic, adj.apomixis
any of several processes of asexual reproduction. Cf. parthenogenesis.astrosphere1.
the central part of an aster, containing the centrosome.2.
the whole aster excluding the centrosome.autecology
the branch of ecology that studies the relation of an organism to its environment. Cf. synecology.auxanography
the branch of microbiology that studies the rate of growth or inhibition exhibited by individual organisms in various plateculture media. —auxanographic, adj.auxesis
growth, especially owing to an increase in cell size. Cf. merisis.
the capacity of some substances to decompose readily by biological process. —biodegradable, adj.biogenesis, biogeny1.
the process by which living organisms develop from other living organisms.2.
the belief that living organisms can only develop from other living organisms. —biogenic, biogenetic, adj.
—biogenetically, biogenically, adv.biogeography
the branch of biology that studies the geographical distribution of animals and plants.biologism
a theory or doctrine based on a biological viewpoint. —biologistic, adj.bioluminescence
the property of some organisms, as fireflies, of producing light. —bioluminescent, adj.biometrics, biometry1.
the calculation of the probable extent of human lifespans.2.
the application to biology of mathematical and statistical theory and methods. —biometric, biometrical, adj.bionomics
ecology. —bionomist, n.
—bionomic, bionomical, adj.biophysiology
the branch of biology that studies the growth, morphology, and physiology of organs. —biophysiologist, n.bioscience
any of the sciences that deal with living organisms.biosphere
that part of the earth where most forms of life exist, specifically, where there is water or atmosphere.biosynthesis
the formation of chemical compounds by living organisms, either by synthesis or degradation. —biosynthetic, adj.biosystematics
the science of the classification of living things. —biosystematic, biosystematical, adj.biotypology
the science or study of biotypes, or organisms sharing the same hereditary characteristics. —biotypologic, biotypological, adj.cataplasia
degeneration of cells or tissues. —cataplastic, adj.cetology
the study of whales. —cetologist, n.
growth or motion in response to a chemical stimulus. —chemotropic, adj.chiasmatypy
the formation of chiasma, the basis for crossing over or the interchange of corresponding chromatid segments of homologous chromosomes with their linked genes. —chiasmatvpic, adj.chorologyBiogeography.
the study of organisms, especially their migrations and distribution. —chorologic, chorological, adj.commensalism
the living together of two organisms in a relationship that is beneficial to one and has no effect on the other. —commensal, adj.consortism
a relationship of mutual dependency between two living organisms.crustaceology
the study of crustaceans. —crustaceologist, n.
a state in which the signs of life of an organism have weakened to the point where they are barely measurable or no longer measurable. —cryptobiotic, adj.ctetology
the branch of biology that studies the origin and development of acquired characteristics. —ctetologic, ctetological, adj.cytogenetics
the branch of biology that studies the structural basis of heredity and variation in living organisms from the points of view of cytology and genetics. —cytogeneticist, n.
—cytogenetic, cytogenetical, adj.cytology
the branch of biology that studies the structure, growth, and pathology of cells. —cytologist, n.
—cytologie, cytological, adj.diakinesis
the final stage of prophase prior to the dissolution of the nuclear membrane. —diakinetic, adj.dialysis
the process whereby colloids and crystalloids separate in solution by diffusion through a membrane. —dialytic, adj.diapause
a period of rest or quiescence between phases of growth or reproduction.digenesis
successive reproduction by two different processes, sexual in one generation and asexual in the following generation. —digenetic, adj.digitigradismZoology.
the condition of walking on the toes. —digitigrade, adj.dysmerogenesis
a form of generation characterized by irregularity of constituent parts, which differ in function, time of budding, etc. Cf. eumerogenesis.
the process of shedding skin or other covering, typical of snakes and some insects. Cf. endysis.
the branch of biology that studies the relations between plants and animals and their environment. Also called bionomics, bionomy
the branch of sociology that studies the environmental spacing and interdependence of people and institutions, as in rural or in urban settings. —ecologist, oecologist, n.
—ecological, oecological, adj.
—ecologically, oecologically, adv.electrobiology
the study of electrical activity in organisms and of the effect of electricity on them. —electrobiologist, n.
the formation and growth of an embryo. —embryogenic, embryogenetic, adj.endogeny
the formation of cells from within. —endogenous, adj.
the growth of new scales, hair, plumage, etc. Cf. ecdysis.
the branch of biology that studies fermentation and enzymes. Also called zymology.
—enzymologie, enzymological, adj.epicenism
the state or quality of combining characteristics of both sexes. —epicenity, n.
the biological theory that germ cells are structureless and the embryo develops through the action of environment on the protoplasm. Cf. preformation.
See also birth
; disease and illness
. —epigenetic, adj.epigenesist
a supporter of the theory of epigenesis.eumerogenesis
generation by unit parts, as in the tape worm, in which each part repeats the one before. Cf. dysmerogenesis.
the process of producing milk.galvanotropism
growth or movement of an organism in response to an electric current. —galvanotropic, adj.gamogenesis
the process of reproduction by the joining of gametes, a form of sexual reproduction. Also called zoogamy.
the branch of biology that studies heredity and variation in plants and animals. —geneticist, n.
a branch of biology that studies animals under germ-free conditions.Haeckelism
theories and doctrines of Ernst Haeckel (1834-1919), German biologist and philosopher, especially the notion “ontogeny recapitulates phylogeny.” —Haeckelian, adj.heterogamete
a gamete differing from the gamete with which it unites in sex, structure, size, or form. Cf. isogamete
the condition of being heterogamous, or reproducing sexually and asexually in alternating generations.2.
the process of indirect pollination. Cf. heterogenesis.
reproduction by a sexual and asexual process alternately. Cf. heterogamy
reproduction in which the parent bears offspring different from itself. Cf. xenogenesis.
the destruction of the cells of one species by the enzymes or lysins of another species. —heterolytic, adj.heterotopism
deviation from the normal ontogenetic sequence with regard to the placing of organs or other parts. Also heterotopism
. See also brain
. —heterotopous, adj.hexiology, hexicology
the study of the effects of environment on an organism’s growth and behavior. —hexiological, hexicological, adj.histogenesis
the growth of organic tissues. —histogenic, histogenetic, adj.histography
a treatise or other work on organic tissues, or histogenesis. —histographer
—histographic, histographical, adj.histolysis
the disintegration or dissolution of organic tissues. —histolytic, adj.homodynamy
the homology of serial segments. Cf. parhomology.homogenesis
the normal course of generation in which the offspring resembles the parent from generation to generation. Cf. heterogenesis.
similarity of form or structure in two or more organisms owing to common descent.2.
similarity in form or structure between different parts of an organism owing to common origin. Cf. homodynamy.
a gamete that is not sexually differentiated from the other gamete with which it unites. Cf. heterogamete.isogamy
reproduction by means of the union of isogametes. —isogamous, adj.isogenesis
the state or process of deriving from the same source or origins, as different parts deriving from the same embryo tissues. Also isogeny.isogonism
production of similar reproductive parts from stocks that are dissimilar, as with certain hydroids. —isogonic, adj.isomorphism
similarity in the form or structure of organisms that belong to a different species or genus. —isomorph
a specialty within cytology that studies the anatomy of cell nuclei with emphasis upon the nature and structure of chromosomes. —karyologist
—karyologic, karyological, adj.kinetogenesis1.
the genesis of organic structure by kinetic processes.2.
the belief that the structure of animals is determined and produced by their movements. —kinetogenetic, adj.Lysenkoism
the theories of the 20th-century Russian geneticist Trofim Lysenko, who argued that somatic and environmental factors have a greater influence on heredity than orthodox genetics has found demonstrable; now generally discredited.macrobiotics
the branch of biology that studies longevity. —macrobiosis, n.
the study of molluscs. —malacologist, n.Mendelianism
the principles or use of Mendel’s law. —Mendelian, n., adj.merisis
any form of growth, especially as a product of cell division. Cf. auxesis.
the process of segmentation in which similar parts unite and form a complex individual entity from the aggregate of the parts. —merogenetic, adj.metagenesis
alternation of generations across reproductive cycles. Cf. xenogenesis.
—metagenetic, metagenic, adj.Michurinism
the biological theory of Ivan Michurin who asserted the fundamental influence of environmental factors on heredity in contradiction of orthodox genetics. —Michurinist
, n. —Michurinite, adj.microtomy
the science or practice of preparing extremely thin slices of tissue, etc, cut by a microtome, for study under the microscope. —microtomist
, n. —microtomic, adj.mimicry
the ability of some creatures to imitate others, either by sound or appearance, or to merge with their environment for protective purposes. See also performing
. —mimic, mimical, adj.mitosis
the normal process of cell division. —mitotic, adj.monogenesis1.
asexual processes of reproduction, as budding.2.
development of an ovum directly into a form like that of the parent, without metamorphosis. —monogenetic, adj.monosymmetry
the state of being zygomorphic, or bilaterally symmetrie, or divisible into symmetrical halves by one plane only. Cf. zygomorphism.
See also physics
. —monosymmetric, monosymmetrical, adj.morphology
the study of the form and structure of plants and animals. —morphologist
, n. —morphologic, morphological, adj.mutualism
the living together of two organisms in a mutually beneficial relationship.neontology
the scientific study of recently living plants and animals. —neontologist, n.
—neontologic, neontological, adj.ontogenesis
ontogeny. —ontogenetic, ontogenetical, adj.ontogeny
the life cycle, development, or developmental history of an organism. Also ontogenesis.
the union of sexually differentiated reproductive cells. —oogamous, adj.oogenesis
the formative process of the ovum in preparation for fertilization and subsequent development. —oogenetic, adj.ooscopy
observation of the development of an embryo inside an egg by means of an ooscope.organogenesis
the origin and growth of organs. —organogenetic, organogenic, adj.organography
the scientific description of the organs of plants and animals. —organographist
, n. —organographic, organographical, adj.organology
the study of the structure and organs of plants and animals. —organologist
, n. —organologic, organological, adj.organonomy1.
the laws of organic life.2.
the doctrine upon which these laws are based. —organonomic, adj.organonymy
the nomenclature of organs. —organonymal
, —organonymic, adj.orthogamy
the property or process of self-fertilization, as in certain plants and animals. —orthogamous, adj.orthogenesis
progressive evolution, leading to the development of a new form, as can be seen through successive generations. See also society
. —orthogenetic, adj.ovism
the theory that the female reproductive cell contains the entire organism and that the male cell does not contribute anything, merely initiating the growth of the female cell.ovology
the study of the formation and structure of animal ova. —ovologist
, n. —ovological, adj.palynology
the science that studies live and fossil spores, pollen grains, and other microscopic plant structures. —polynologist, n.
the uniting of two individual organisms or animals anatomically and physiologically, under either experimental or natural conditions. —parabiotic, adj.parasitism
the living together of two organisms in a relationship that is beneficial to one and destructive to the other. —parasitic, parasitical, adj.parasitology
the branch of biology that studies parasites and parasitism. —parasitologist
the biological process of imitative homodynamy. —parhomologous
reproduction without fertilization, as certain ova, seeds and spores, insects, algae, etc. Also called unigenesis
. —parthenogenetic, parthenogenic, adj.photoperiodism, photoperiodicity
the effect on the growth and reproduction of plants or animals of varying exposures to light and darkness. Cf. thermoperiodism. —photoperiod, n.
the synthesis of complex organic substances from carbon dioxide, water, and inorganic salts, with sunlight as the energy source and a catalyst such as chlorophyll. —photosynthetic, adj.phototropism
growth or motion in response to light. —phototropic, adj.physiogeny
the history or science of the development or evolution of vital activities in the individual and the genesis of organic functions; a division of ontogeny. Also called physiogenesis.
—physiogenetic, physiogenic, adj.phytobiology
plant biology. —phytobiologist, n.
the existence of a plant or animal in two or more distinct forms during a life cycle. Also called polymorphism.
—pleomorphic, pleomorphous, adj.polygenesis1.
derivation from more than one kind of cell in the generative process.2.
Also called polygenism
. the theory that different species have descended from different original ancestors. Cf. monogenesis.
—polygenic, polygenetic, adj.polyphagia
the tendency to eat a wide variety of food. —polyphagist
the character of being made up of a number of smaller organisms that are acting as a colony. —polyzoic, adj.preformation
the theory that germ cells contain every part of the future organism in miniature form, future development being only a matter of increase in size. Cf. epigenesis
the theory that an organism is fully formed at conception and that reproduction is thereafter simply a process of growth. —preformationist, n.protozoology
the study of protozoa, especially of those that cause disease. —protozoological, adj.
the branch of biology that studies the interactions of body and mind, especially as exhibited in the nervous system.2.
psychology as studied in terms of biology. —psychobiologist, n.
—psychobiologic, psychobiological, adj.speciation
the formation of new species.spermism
an obsolete biological theory that stated that sperm contained the preformed germ or the embryo. —spermist, n.spongology
the science and study of the sponges. —spongologist, n.sporogenesis1.
the process of reproduction by means of spores.2.
the formation and growth of spores. —sporogenetic, sporogenous, adj.stereotaxis
orientation or movement of an organism in response to the stimulus of a solid object. Cf. stereotropism.
growth or movement determined by contact with a solid. Cf. stereotaxis.
selective breeding to develop strains with particular characteristics. —stirpicultural, adj.superfetation
a conception occurring during a pregnancy from an earlier conception.symbiosis
the living together of two dissimilar organisms; the relationship may be beneficial to both (mutualism
and symbiosis), beneficial to one without effect on the other (commensalism
), beneficial to one and detrimental to the other (parasitism
), detrimental to the first without any effect on the other (amensalism), or detrimental to both (synnecrosis
). —symbiotic, adj.symphytismRare.
the tendency of two separate elements to grow together. —symphytic, adj.synecology
the branch of ecology that studies the relation of various groups of organisms to their common environment. Cf. autecology.synnecrosis
the living together of two organisms in a mutually destructive relationship.teratology
the branch of biology that studies abnormal formations in animals or plants. —teratologist
, n. —teratologie, teratological, adj.testaceology
the study of the shell-bearing animals. —testaceological, adj.thermoperiodism
the effect on the growth and reproduction of plants or animals of timed exposures to varied temperatures. —thermoperiod, n.
the study of animals. —therologist
—therologic, therological, adj.thigmotaxis
involuntary response or reaction to the touch of outside objects or bodies, as in motile cells. —thigmotactic
the submicroscopic, elemental structure of protoplasm. —ultrastructural
the process of gestation taking place in the womb from conception to birth.xenogenesis1.
abiogenesis; spontaneous generation.2.
metagenesis, or alternation of generations.3.
production of an offspring entirely different from either of the parents. —xenogenetic, xenogenic, adj.zoogamy
gamogenesis. —zoogamous, adj.zygomorphism
the state or quality of being bilaterally symmetrical, as certain organisms. Cf. monosymmetry.
—zygomorphic, zygomorphous, adj.zygosis
the biological process of conjugation; the union of cells or gametes. —zygose
the process in which a zymogen becomes an enzyme, as in the fermentation process. —zymogenic, zymogenous, adj.zymology