See also animals; botany; cells; life; organisms; plants; zoology.
the process of generation of living organisms from inanimate matter; spontaneous generation. —abiogenetic, adj.
asexual reproduction. —agamogenetic, adj.
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.
the living together of two organisms in a relationship that is destructive to one and has no effect on the other.
gradual change in type, usually from a lower to a higher type. Also anamorphosis
, (Obsolete) anamorphosy
. —anamorphic, adj.
connection between parts that have branched off from each other at some earlier point. —anastomotic, adj.
a form of reproduction in which dissimilar gametes, often dirfering in size, unite. —anisogamous, anisogamic, adj.
any of several processes of asexual reproduction. Cf. parthenogenesis.
the central part of an aster, containing the centrosome.
the whole aster excluding the centrosome.
the branch of ecology that studies the relation of an organism to its environment. Cf. synecology.
the branch of microbiology that studies the rate of growth or inhibition exhibited by individual organisms in various plateculture media. —auxanographic, adj.
growth, especially owing to an increase in cell size. Cf. merisis.
the capacity of some substances to decompose readily by biological process. —biodegradable, adj.
the process by which living organisms develop from other living organisms.
the belief that living organisms can only develop from other living organisms. —biogenic, biogenetic, adj.
—biogenetically, biogenically, adv.
the branch of biology that studies the geographical distribution of animals and plants.
a theory or doctrine based on a biological viewpoint. —biologistic, adj.
the property of some organisms, as fireflies, of producing light. —bioluminescent, adj.
the calculation of the probable extent of human lifespans.
the application to biology of mathematical and statistical theory and methods. —biometric, biometrical, adj.
ecology. —bionomist, n.
—bionomic, bionomical, adj.
the branch of biology that studies the growth, morphology, and physiology of organs. —biophysiologist, n.
any of the sciences that deal with living organisms.
that part of the earth where most forms of life exist, specifically, where there is water or atmosphere.
the formation of chemical compounds by living organisms, either by synthesis or degradation. —biosynthetic, adj.
the science of the classification of living things. —biosystematic, biosystematical, adj.
the science or study of biotypes, or organisms sharing the same hereditary characteristics. —biotypologic, biotypological, adj.
degeneration of cells or tissues. —cataplastic, adj.
the study of whales. —cetologist, n.
growth or motion in response to a chemical stimulus. —chemotropic, adj.
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.
the study of organisms, especially their migrations and distribution. —chorologic, chorological, adj.
the living together of two organisms in a relationship that is beneficial to one and has no effect on the other. —commensal, adj.
a relationship of mutual dependency between two living organisms.
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.
the branch of biology that studies the origin and development of acquired characteristics. —ctetologic, ctetological, adj.
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.
the branch of biology that studies the structure, growth, and pathology of cells. —cytologist, n.
—cytologie, cytological, adj.
the final stage of prophase prior to the dissolution of the nuclear membrane. —diakinetic, adj.
the process whereby colloids and crystalloids separate in solution by diffusion through a membrane. —dialytic, adj.
a period of rest or quiescence between phases of growth or reproduction.
successive reproduction by two different processes, sexual in one generation and asexual in the following generation. —digenetic, adj.
the condition of walking on the toes. —digitigrade, adj.
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.
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.
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.
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.
a supporter of the theory of epigenesis.
generation by unit parts, as in the tape worm, in which each part repeats the one before. Cf. dysmerogenesis.
the process of producing milk.
growth or movement of an organism in response to an electric current. —galvanotropic, adj.
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.
theories and doctrines of Ernst Haeckel (1834-1919), German biologist and philosopher, especially the notion “ontogeny recapitulates phylogeny.” —Haeckelian, adj.
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.
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.
deviation from the normal ontogenetic sequence with regard to the placing of organs or other parts. Also heterotopism
. See also brain
. —heterotopous, adj.
the study of the effects of environment on an organism’s growth and behavior. —hexiological, hexicological, adj.
the growth of organic tissues. —histogenic, histogenetic, adj.
a treatise or other work on organic tissues, or histogenesis. —histographer
—histographic, histographical, adj.
the disintegration or dissolution of organic tissues. —histolytic, adj.
the homology of serial segments. Cf. parhomology.
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.
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.
reproduction by means of the union of isogametes. —isogamous, adj.
the state or process of deriving from the same source or origins, as different parts deriving from the same embryo tissues. Also isogeny.
production of similar reproductive parts from stocks that are dissimilar, as with certain hydroids. —isogonic, adj.
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.
the genesis of organic structure by kinetic processes.
the belief that the structure of animals is determined and produced by their movements. —kinetogenetic, adj.
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.
the branch of biology that studies longevity. —macrobiosis, n.
the study of molluscs. —malacologist, n.
the principles or use of Mendel’s law. —Mendelian, n., adj.
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.
alternation of generations across reproductive cycles. Cf. xenogenesis.
—metagenetic, metagenic, adj.
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.
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.
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.
the normal process of cell division. —mitotic, adj.
asexual processes of reproduction, as budding.
development of an ovum directly into a form like that of the parent, without metamorphosis. —monogenetic, adj.
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.
the study of the form and structure of plants and animals. —morphologist
, n. —morphologic, morphological, adj.
the living together of two organisms in a mutually beneficial relationship.
the scientific study of recently living plants and animals. —neontologist, n.
—neontologic, neontological, adj.
ontogeny. —ontogenetic, ontogenetical, adj.
the life cycle, development, or developmental history of an organism. Also ontogenesis.
the union of sexually differentiated reproductive cells. —oogamous, adj.
the formative process of the ovum in preparation for fertilization and subsequent development. —oogenetic, adj.
observation of the development of an embryo inside an egg by means of an ooscope.
the origin and growth of organs. —organogenetic, organogenic, adj.
the scientific description of the organs of plants and animals. —organographist
, n. —organographic, organographical, adj.
the study of the structure and organs of plants and animals. —organologist
, n. —organologic, organological, adj.
the laws of organic life.
the doctrine upon which these laws are based. —organonomic, adj.
the nomenclature of organs. —organonymal
, —organonymic, adj.
the property or process of self-fertilization, as in certain plants and animals. —orthogamous, adj.
progressive evolution, leading to the development of a new form, as can be seen through successive generations. See also society
. —orthogenetic, adj.
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.
the study of the formation and structure of animal ova. —ovologist
, n. —ovological, adj.
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.
the living together of two organisms in a relationship that is beneficial to one and destructive to the other. —parasitic, parasitical, adj.
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.
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.
growth or motion in response to light. —phototropic, adj.
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.
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.
derivation from more than one kind of cell in the generative process.
Also called polygenism
. the theory that different species have descended from different original ancestors. Cf. monogenesis.
—polygenic, polygenetic, adj.
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.
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.
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.
psychology as studied in terms of biology. —psychobiologist, n.
—psychobiologic, psychobiological, adj.
the formation of new species.
an obsolete biological theory that stated that sperm contained the preformed germ or the embryo. —spermist, n.
the science and study of the sponges. —spongologist, n.
the process of reproduction by means of spores.
the formation and growth of spores. —sporogenetic, sporogenous, adj.
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.
a conception occurring during a pregnancy from an earlier conception.
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.
the tendency of two separate elements to grow together. —symphytic, adj.
the branch of ecology that studies the relation of various groups of organisms to their common environment. Cf. autecology.
the living together of two organisms in a mutually destructive relationship.
the branch of biology that studies abnormal formations in animals or plants. —teratologist
, n. —teratologie, teratological, adj.
the study of the shell-bearing animals. —testaceological, adj.
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.
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.
abiogenesis; spontaneous generation.
metagenesis, or alternation of generations.
production of an offspring entirely different from either of the parents. —xenogenetic, xenogenic, adj.
gamogenesis. —zoogamous, adj.
the state or quality of being bilaterally symmetrical, as certain organisms. Cf. monosymmetry.
—zygomorphic, zygomorphous, adj.
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.