44. Biology

See also 16. ANIMALS ; 54. BOTANY ; 72. CELLS ; 244. LIFE ; 302. ORGANISMS ; 319. PLANTS ; 430. ZOOLOGY .

abiogenesis

the process of generation of living organisms from inanimate matter; spontaneous generation. —abiogenetic, adj. —abiogenetically, adv.

agamogenesis

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.

astrosphere

1. 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. —auxetic, adj.

biodegradability

the capacity of some substances to decompose readily by biological process. —biodegradable, adj.

biogenesis, biogeny

1. 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, biometry

1. 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, bionomy

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

biosystematy.

biosystematy, 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. —cetological, adj.

chemotropism

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.

chorology

Biogeography. 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. —crustaceological, adj.

cryptobiosis

Medicine. 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.

digitigradism

Zoology. 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. —dysmerogenetic, adj.

ecdysis

the process of shedding skin or other covering, typical of snakes and some insects. Cf. endysis. —ecdysial, adj.

ecology, oecology

1. the branch of biology that studies the relations between plants and animals and their environment. Also called bionomics, bionomy .

2. 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. —electrobiological, adj.

embryogeny

the formation and growth of an embryo. —embryogenic, embryogenetic, adj.

endogenesis, endogeny

the formation of cells from within. —endogenous, adj. —endogenicity, n.

endysis

the growth of new scales, hair, plumage, etc. Cf. ecdysis. —endysial, adj.

enzymology

the branch of biology that studies fermentation and enzymes. Also called zymology. —enzymologist, n. —enzymologie, enzymological, adj.

epicenism

the state or quality of combining characteristics of both sexes. —epicenity, n. —epicene, adj.

epigenesis

the biological theory that germ cells are structureless and the embryo develops through the action of environment on the protoplasm. Cf. preformation. See also 46. BIRTH ; 122. DISEASE and ILLNESS ; 179. GEOLOGY . —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. —eumerogenetic, adj.

galactosis

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. —gamogenetic, adj.

genetics

the branch of biology that studies heredity and variation in plants and animals. —geneticist, n. —genetic, adj.

gnotobiotics

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 .

heterogamy

1. the condition of being heterogamous, or reproducing sexually and asexually in alternating generations.

2. the process of indirect pollination. Cf. heterogenesis. —heterogamous, adj.

heterogenesis

1. reproduction by a sexual and asexual process alternately. Cf. heterogamy .

2. reproduction in which the parent bears offspring different from itself. Cf. xenogenesis. —heterogenetic, adj.

3. abiogenesis.

heterolysis

the destruction of the cells of one species by the enzymes or lysins of another species. —heterolytic, adj.

heterotopism

heterotopy.

heterotopy, heterotopia

deviation from the normal ontogenetic sequence with regard to the placing of organs or other parts. Also heterotopism . See also 56. BRAIN . —heterotopous, adj.

hexiology, hexicology

the study of the effects of environment on an organism’s growth and behavior. —hexiological, hexicological, adj.

histogenesis, histogeny

the growth of organic tissues. —histogenic, histogenetic, adj.

histography

a treatise or other work on organic tissues, or histogenesis. —histographer , n. —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. —homogenetic , adj.

homology

1. 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. —homologous, adj.

isogamete

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 , n. —isomorphic, adj.

karyology

a specialty within cytology that studies the anatomy of cell nuclei with emphasis upon the nature and structure of chromosomes. —karyologist , n. —karyologic, karyological, adj.

kinetogenesis

1. 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. —macrobiotist, n.

malacology

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. —meristic, adj.

merogenesis

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 310. PERFORMING . —mimic, mimical, adj.

mitosis

the normal process of cell division. —mitotic, adj.

monogenesis

1. 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 316. 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. —ontogenic, adj. —ontogenic, adj.

oogamy

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, organogeny

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.

organonomy

1. 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 376. 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. —polynological, adj.

parabiosis

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 , n.

parhomology

the biological process of imitative homodynamy. —parhomologous , adj.

parthenogenesis, parthogeny

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. —photoperiodic, adj.

photosynthesis

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. —phytobiological, adj.

pleomorphism, pleomorphy

the existence of a plant or animal in two or more distinct forms during a life cycle. Also called polymorphism. —pleomorphic, pleomorphous, adj.

polygenesis

1. 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, polyphagy

the tendency to eat a wide variety of food. —polyphagist , n. —polyphagic, adj.

polyzoism

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 .

preformationism

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. —protozoologist , n.

psychobiology

1. 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.

sporogenesis

1. 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. —stereotactic, adj.

stereotropism

growth or movement determined by contact with a solid. Cf. stereotaxis. Also thigmotropism. —stereotropic, adj.

stirpiculture

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.

symphytism

Rare. 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, thermoperiodicity

the effect on the growth and reproduction of plants or animals of timed exposures to varied temperatures. —thermoperiod, n. —thermoperiodic, adj.

therology

the study of animals. —therologist , n. —therologic, therological, adj.

thigmotaxis

involuntary response or reaction to the touch of outside objects or bodies, as in motile cells. —thigmotactic , adj.

thigmotropism

stereotropism. —thigmotropic , adj.

ultrastructure

the submicroscopic, elemental structure of protoplasm. —ultrastructural , adj.

unigenesis

parthenogenesis. —unigenetic , adj.

uterogestation

the process of gestation taking place in the womb from conception to birth.

xenogenesis, xenogeny

1. 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 , adj.

zymogenesis

the process in which a zymogen becomes an enzyme, as in the fermentation process. —zymogenic, zymogenous, adj.

zymology

enzymology. —zymologist , n. —zymologic , adj.

Biology

What role do computers play in the study of biology? Most people understand that computers produce spreadsheets, help analyze data, graph results of experiments, and prepare final reports for presentations. Although computers are workhorses in these areas, computers and the Internet are considered vital in other ways to many different fields of biology and research. In some cases, computer science and biology (along with chemistry, physics, and mathematics) are woven so tightly together they have become inseparable.

Scientific Organizations

The Centers for Disease Control and Prevention, or CDC, is a U.S. government agency headquartered in Atlanta, Georgia. The goal of the CDC is to protect the health and safety of U.S. citizens at home, work, and abroad through the detection, treatment, and prevention of health-related issues. The CDC has an integral role in the tracking of infectious diseases and uses computers in a multitude of ways.

This is illustrated by the Division of Parasitic Diseases (DPD), a branch of the CDC. The DPD extends knowledge and control of parasites and parasitic diseases primarily through the use of the Internet and extensive computer databases. At the agency's Internet web site, thousands of known parasites can be viewed (including microscopic slides). This aids in the identification of parasitic organisms and the diseases they cause.

Through the web site, the DPD supplies information to health care workers on how to recognize and treat possible cases of parasite-caused disease. Health care professionals can also find out how to get and submit samples for a diagnosis. Experts at the DPD will answer e-mailed questions and review digital images of slides of suspected parasites. Confirmed cases of parasitic infection are reported back to the DPD and are added to its extensive databases. Through the use of statistical analysis, trends of parasitic infections are tracked. Armed with this information, experts at the CDC are able to identify populations vulnerable to parasites. Steps can then be taken to find infected individuals for treatment and limit exposure to others, keeping people healthy.

Originally, the CDC was founded to eliminate malaria. It now tracks a multitude of infectious diseases, from AIDS to the common flu. In 2001, the CDC was engaged in building a National Electronic Disease Surveillance System, which through the Internet creates a broad-based and comprehensive system linking local and national health departments regardless of differing computer platforms and software. This new system will allow faster detection of and more rapid intervention against public health threats.

The National Institutes of Health, or NIH, is another U.S. agency that extensively uses computers and the Internet in its collection and application of biological information. The National Center for Biotechnology Information (NCBI), a subdivision of the NIH, maintains expansive databases on their computers, including known gene sequences, for molecular biology researchers all over the world. The largest biomedical research facility in the world, the NIH is headquartered in Bethesda, Maryland.

Bioinformatics

One field that has proved essential to gene sequencing is bioinformatics. Researchers in this field develop algorithms and software to allow enormous amounts of biological information to be processed. Bioinformatics is essential to molecular biologists working on "breaking" genetic codes.

With only ten percent of the world's bacteria identified, gene sequencing is also being used to examine the DNA (deoxyribonucleic acid) of various bacteria. Scientists expect to use this method to identify previously undiscovered bacteria in what have always been considered inhospitable environments around the world, such as thermal springs, oil fields, or areas deep under the Earth's crust. Research on this amazing diversity of life contributes to humankind's knowledge of biological processes, and holds much promise for future researchers.

Bioengineering and Biomedical Engineering

Bioengineering is a new study that brings the science of engineering into the science of cell and molecular biology. Bioengineers use computers to study the structure and processes of living cells and organisms. The advances from bioengineering are seen in fields as diverse as manufacturing, chemical industries, defense industries, electronics, and agriculture. For example, through bioengineering one can detect harmful pollutants in the environment and harmful microorganisms in food.

Biomedical engineering, however, draws from many fields of engineering, such as electrical, mechanical, and chemical engineering. It is used to advance medicine and health care. Computers are used to analyze the functions of cells, and then to design mechanical reproductions to master that function. Computers are needed to use the components that result. One well-known example of biomedical engineering is the artificial heart.

Another result of biomedical engineering is the mechanization of lab tests. Routine lab tests used to be conducted by hand. The process of, for instance, checking a complete blood cell count required several time-consuming steps. Frequently the test was repeated to rule out possible lab error. Through biomedical engineering, the testing processing is done quickly, efficiently, and with very little likelihood of lab error. A blood sample is marked with the patient's bar code moments after the blood is drawn from the patient. Once it is put in the automated machine, the computer takes over the processing. In some tests, computerized image analysis is used for a definitive diagnosis. The computer then directs the test results where needed. The use of automated lab tests lowers costs while vastly increasing efficiency, speed, and accuracy.

Environmental Biology

Computers are also valuable in environmental studies. Conservation agencies, such as the U.S. Fish and Wildlife Service, use computers in several ways. One key to successful conservation efforts is effective communication with local conservation groups, state officials, and local legislative bodies (who frequently decide upon important zoning issues). Through the Internet, a variety of educational materials are easily accessible.

Although the U.S. Fish and Wildlife Service's goal is to standardize equipment and provide reference material and electronic communication within the service, particularly to remote field offices, these efforts are seriously hampered by lack of funding for equipment upgrades. In other conservation efforts, computers are being used to model natural ecological systems for study. Satellite remote sensing, such as imagery and telemetry , make regional and landscape mapping easier, more accurate, and cost effective. This helps environmental biologists gather information more effectively.

With the growing sophistication of research needs and resources and the increased use of the Internet to gather, share, and analyze scientific data, evidence suggests that computers will continue to play a vital part in the study of biology in its many applications.

see also Molecular Biology; Physics; Scientific Visualization.

Mary McIver Puthawala and Anwer H. Puthawala

Internet Resources

Centers for Disease Control and Prevention Web Site. <http://www.cdc.gov>

"DPDx—Identification and Diagnosis of Parasites of Public Health Concern." Centers for Disease Control and Prevention. <http://www.dpd.cdc.gov/dpdx/HTML/Aboutdpdx.htm>

Massey, Adrianne. "What Is Biotechnology?" Biotechnology Industry Organization. <http://www.bio.org/aboutbio/guide2000/whatis.html>

Biology

Biology (from the Greek bios, meaning "life") is the scientific study of all forms of life, including plants, animals, and microorganisms.

Biology is composed of many fields, including microbiology, the study of microscopic organisms such as viruses and bacteria; cytology, the study of cells; embryology, the study of development; genetics, the study of heredity; biochemistry, the study of the chemical structures in living things; morphology, the study of the anatomy of plants and animals; taxonomy, the identification, naming, and classification of organisms; and physiology, the study of how organic systems function and respond to stimulation. Biology often interacts with other sciences, such as psychology. For example, animal behaviorists would need to understand the biological nature of the animal they are studying in order to evaluate a particular animal's behavior.

History of biological science

The history of biology begins with the careful observation of the external aspects of organisms and continues with investigations into the functions and interrelationships of living things.

The fourth-century b.c. Greek philosopher Aristotle is credited with establishing the importance of observation and analysis as the basic approach for scientific investigation. He also organized the basic principles of dividing and subdividing plants and animals, known as classification. By a.d. 200, studies in biology were centered in the Arab world. Most of the investigations during this period were made in medicine and agriculture. Arab scientists continued this activity throughout the Middle Ages (400–1450).

Words to Know

Classification: The system of arranging plants and animals in groups according to their similarities.

Genetic engineering: Altering hereditary material (by a scientist in a lab) by interfering in the natural genetic process.

Germ theory of disease: The belief that disease is caused by germs.

Microorganism: An organism that cannot be seen without magnification under a microscope.

Molecular biology: A branch of biology that deals with the physical and chemical structure of living things on the molecular level.

Natural selection: Process by which those organisms best adapted to their environment survive and pass their traits to offspring.

Scientific investigations gained momentum during the Renaissance (a period of rebirth of art, literature, and science in Europe from the fourteenth to the seventeenth century). Italian Renaissance artists Leonardo da Vinci (1452–1519) and Michelangelo (1475–1564) produced detailed anatomical drawings of human beings. At the same time, others were dissecting cadavers (dead bodies) and describing internal anatomy. By the seventeenth century, formal experimentation was introduced into the study of biology. William Harvey (1578–1657), an English physician, demonstrated the circulation of the blood and so initiated the biological discipline of physiology.

So much work was being done in biological science during this period that academies of science and scientific journals were formed, the first being the Academy of the Lynx in Rome in 1603. The first scientific journals were established in 1665 in France and Great Britain.

The invention of the microscope in the seventeenth century opened the way for biologists to investigate living organisms at the cellular level—and ultimately at the molecular level. The first drawings of magnified life were made by Francesco Stelluti, an Italian who published drawings in 1625 of a honeybee magnified to 10 times its normal size.

During the eighteenth century, Swedish botanist Carolus Linnaeus (1707–1778) developed a system for naming and classifying plants and animals that replaced the one established by Aristotle (and is still used today). Based on his observations of the characteristics of organisms, Linnaeus created a ranked system in which living things were grouped according to their similarities, with each succeeding level possessing a larger number of shared traits. He named these levels class, order, genus, and species. Linnaeus also popularized binomial nomenclature, giving each living thing a Latin name consisting of two parts—its genus and species—which distinguished it from all other organisms. For example, the wolf received the scientific name Canis lupus, while humans became Homo sapiens.

In the nineteenth century, many explorers contributed to biological science by collecting plant and animal specimens from around the world. In 1859, English naturalist Charles Darwin (1809–1882) published The Origin of Species by Means of Natural Selection, in which he outlined his theory of evolution. Darwin asserted that living organisms that best fit their environment are more likely to survive and pass their characteristics on to their offspring. His theory of evolution through natural selection was eventually accepted by most of the scientific community.

French microbiologist and chemist Louis Pasteur (1822–1895) showed that living things do not arise spontaneously. He conducted experiments confirming that microorganisms cause disease, identified several disease-causing bacteria, and also developed the first vaccines. By the end of the nineteenth century, the germ theory of disease was established by German physician Robert Koch (1843–1910), and by the early twentieth century, chemotherapy (the use of chemical agents to treat or control disease) was introduced. The use of antibiotics became widespread with the development of sulfa drugs in the mid-1930s and penicillin in the early 1940s.

From the nineteenth century until the end of the twentieth century, the amount of research and discovery in biology has been tremendous. Two fields of rapid growth in biological science today are molecular biology and genetic engineering.

[See also Biochemistry; Botany; Ecology; Evolution; Genetics; Molecular biology; Physiology ]

Biology

Biology is defined as the science of living organisms. The diversity of activities contained within the field of biology is immense, and includes research into the origins, functions, and interrelationships of organisms, as well as the technological application of biological knowledge.

The idea that living forms gradually emerged through a process of evolution from much simpler forms in a branch-like system is no longer a contested issue in biology. Research into the fossil record, or palaeontology, and other subdisciplines of biology, such as comparative anatomy, biogeography, embryology, and genetics, have helped to trace patterns of common descent, including those between humans and primates. Charles Darwin's (1809–1882) theory of natural selection forms the basis of evolutionary theory, though other processes such as genetic drift and molecular drive have been proposed in addition. The relative pace of natural selection continues to be the subject of ongoing debate. The dynamics of genetic change in a population include mutation rates, migration of individuals from one population to another, genetic drift, and natural selection. The anatomical and behavioral differences within and among known hominid species can be traced. Other extinct species of humans have been discovered, though the consensus seems to be that Homo sapiens has a single original ancestor, who probably lived in Africa.

Ecology has enabled scientists to study more closely the way living organisms relate to each other. While early ecologists believed that ecosystems were stable and in equilibrium, this thesis has gradually given way to a more dynamic view, where contingency is predominant. Ecology includes not just the relationship between local communities of living things, but also extends to wider global and planetary systems. Some ecologists emphasize the idea of self-regulation within living systems, or autopoiesis, as well as the idea of emergence, understood in terms of properties that cannot simply be explained by upward causation from molecular mechanisms. Biosemiotics applies concepts from semiotics to elaborate the specific emergence of meaning, intentionality, and a psychic world. The latter can be compared to sociobiology, which tries to explain particular aspects of animal and human behavior by envisaging a shared biological and genetic origin.

The use of biological research to address specific human needs through biotechnology was given a radical boost following the discovery of the structure of deoxyribonucleic acid (DNA) in the 1950s. The ability to move genes from one species to the next has opened up the possibility of even more radical human intervention in the evolutionary process. The most controversial changes are those that manipulate the human species. Nonetheless, changes in the nonhuman world also raise questions that are of concern to environmentalists. The general increase in technological and industrial activity has put considerable strain on the planet, which many biologists consider to be near its carrying capacity in terms of its ability to support the human population. Loss of species through, for example, habitat destruction, climate change, or direct exploitation has promoted a growing concern for an environmental ethic among secular and religious communities. Such questions move biology outside the realm of pure science into the realms of the politics and the economics of poverty, posterity, and social justice.

See also Biosemiotics; Evolution; Life, Origins of; Life, Religious and Spiritual Aspects; Life Sciences; Sociobiology

celia deane-drummond

Biology

Biology is defined as the "study of life." The term life refers to all organisms (plants, animals, bacteria, fungi, and protists) inhabiting Earth and its atmosphere. Both scientists and laypeople are drawn to biology because it seeks to answer the question of how life began. All of the acquired evidence points to a single origin for all living things.

The study of evolution shows that there are significant similarities among organisms that are not obviously related. Virtually every organism uses the same genetic code to builds its proteins , from the tiniest bacterium to the blue whale and the giant sequoia. A fungus and a horse break down sugar to release energy using (more or less) the same enzymes . Indeed, evolution, the gradual change in a population over time, serves as a unifying concept in biology.

The more related two species of multicellular organisms are, the more similar their anatomies in almost all cases. Species that rely heavily on one another for life evolve in response to each other's habits and characteristics. Researchers use animals closely related to humans in order to predict the effects of new drugs or surgical techniques on human subjects, taking advantage of evolutionary relationships that yield similar anatomies and physiologies in different organisms.

Biology's Subdisciplines

Biology encompasses many diverse subdisciplines. Systematics is the study of the diversity and classification of organisms. Cell biology is concerned with the structure and function of cells but also includes the interactions that occur between cells (for example, the signaling that occurs among different cells of the human body). The field of ecology considers interactions among organisms that inhabit the same area. For example, ecologists might study the changes in population size of a group of birds in response to the presence of a predator, or the impact of pollution on frog populations. Someone interested in medicine would need a solid background in anatomy, the study of the structure of the bodies of animals and how different components of the body relate to one another.

Physiology, which is closely related to anatomy, describes the mechanisms by which these different components perform. One might also study the anatomy and physiology of plants to learn how different tissues within a plant perform and interact. Microbiology, a field driven largely by the study of disease, is concerned with the structure, function, and interactions of microorganisms. Genetics is concerned with the inheritance of characteristics from parents to offspring, and the expression of genes to create the living organism.

Much emphasis in biology is in biotechnology, the use of organisms to create products. This field opens unimaginable possibilities for the diagnosis and treatment of hereditary diseases, production of drugs, and advancement of agriculture. At the same time, these prospects will challenge scientists with serious ethical considerations in the years to come, as the use of biotechnology requires scientists to manipulate the course of evolution.

see also Biodiversity; Biotechnology; Ecology; Evolution

Karen Gunnison Ballen

Bibliography

Krogh, David. Biology: A Guide to the Natural World. Upper Saddle River, NJ: Prentice Hall, 2000.

biology the science that deals with living things. It is broadly divided into zoology , the study of animal life, and botany , the study of plant life. Subdivisions of each of these sciences include cytology (the study of cells), histology (the study of tissues), anatomy or morphology, physiology, and embryology (the study of the embryonic development of an individual animal or plant). Also included in biological studies are the sciences of genetics, evolution, paleontology, and taxonomy or systematics, the study of classification. The methods and attitudes of other sciences are brought to the study of biology in such fields as biochemistry (physiological chemistry), biophysics (the physics of life processes), bioclimatology and biogeography (ecology), bioengineering (the design of artificial organs), biometry or biostatistics, bioenergetics, and biomathematics. Evidences of early human observations of nature are seen in prehistoric cave art. Biological concepts began to develop among the early Greeks. The biological works of Aristotle include his observations and classification of his large collections of animals. The invention of the microscope in the 16th cent. gave a great stimulus to biology, broadening and deepening its scope and creating the sciences of microbiology, the study of microscopic forms of life, and microscopy, the microscopic study of living cells. Among the many who contributed to the science are Claude Bernard, Cuvier, Darwin, T. H. Huxley, Lamarck, Linnaeus, Mendel, and Pasteur. See marine biology .

Bibliography: See T. Lenoir, The Strategy of Life (1989); C. A. Villee et al., Biology (3d ed. 1989); N. A. Campbell, Biology (3d ed. 1993).

bi·ol·o·gy / bīˈäləjē/ (abbr.: biol.) • n. the study of living organisms, divided into many specialized fields that cover their morphology, physiology, anatomy, behavior, origin, and distribution. ∎  the plants and animals of a particular area: the biology of Chesapeake Bay. ∎  the physiology, behavior, and other qualities of a particular organism or class of organisms: human biology. DERIVATIVES: bi·ol·o·gist / -jist/ n.

biology Science of life and living organisms. Its branches include botany (plants), zoology (animals), ecology (habitats and species' interaction), physiology (structure of living things), cytology (cells), genetics (inheritance), taxonomy (classification), embryology (embryos), and microbiology (microorganisms). These sciences deal with the origin, history, structure, development, and function of living organisms, their relationships to each other and their environment, and the differences between living and non-living organisms.

biology (by-ol-ŏji) n. the study of living organisms including their structure and function and their relationships with one another and with the inanimate world.
—biological (by-ŏ-loj-ik-ăl) adj. —biologist n.

biology The study of living organisms, which includes their structure (gross and microscopical), functioning, origin and evolution, classification, interrelationships, and distribution.

Biology. See Biological Sciences.

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