Biology Glossary
abdomen / part of an arthropod's body that is behind the thoraxpg 735 textbookabiotic factors / Non-living factor in an ecosystem such as temperature, water, wind, weather, sunlight, soil and mineralspg 402 of textbook.
ABO blood group / four common blood types (A, B, AB, and O) and the protein markers that distinguish them pg 927 textbook
absorption / process by which nutrients move out of one system and into anotherpg 982
abyssal zone / depth of the ocean that lies below 200 meters and is in complete darkness
Acclimatization / Adaptation of an organism to a new environment.
acid / compound that donates a proton (H+) when dissolved in a solutionpg 42 textbook
acid rain / precipitation produced when pollutants in the atmosphere cause the pH of rain to decreasepg 489 textbook
actin / filament that is pulled by myosin filaments to cause muscle contraction (pp. 1008)
Action letter / An official FDA communication that informs an NDA or BLA sponsor of a decision by the agency. An approval letter allows commercial marketing of the product.
action potential / Fast, moving change in elextrical charge across a neuron's membrane; also called an impulse (pp. 878)
activation energy / energy input necessary to initate a chemical reaction (pp. 53)
Active immunity / A type of acquired immunity whereby resistance to a disease is built up by either having the disease or receiving a vaccine to it. (pp. 948)
active immunity / immunity that occurs after the body resonds to an antigen (pp. 948)
active transport / energy-requiring movement of molecules across a membrane from a region of lower concentration to a region of higher concentration (pp.89)
adaptation / inherited trait that is selcted for over time because it allows organism to better survive in their environment (pp;10 ;302)
adaptive radiation / process by which one species evolves and gives rise to many descendant species that occupy different ecological niches (pp. 351)
addiction / uncontrollable physical and mental need for something (pp.893)
adenosine triposphate / high-energy molecule that contains, within its bonds, energy that cells can use (pp.100)
adensosine diphosphate (ADP) / low-energy molecule that can be converted to ATP (pp.101)
adhesion / attraction between molecules of different substances (pp. 41)
Adjuvant / Insoluble material that increases the formation and persistence of antibodies when injected with an antigen.
adolescence / period of life beginning at puberty and ending at adulthood (pp. 1042)
ADP / adenosine diphosphate (pp.101)
adulthood / period of life when a person is fully developed and physical growth stops (pp.1043)
aerobic / process that requires oxygen to occur (pp.113)
Aerobic / Needing oxygen for growth.
Agrobacterium tumefaciens / A common soil bacterium used as a vector to create transgenic plants.
AIDS / Acquired immune deficiency syndome (AIDS) condition characterized by having several infections and very few T cells; caused by HIVpg 963 texbook
air sac / air-filled space that connects to a bird's lungs, aiding in breathing (pp. 801)
airfoil / surface, such as a bird's wing whose shape moves air faster over the top trhan underneath it, allowing flight to occur (pp.799)
algae / photosynthetic plantlike protists (pp. 581)
alkaloid / chemical produced by plants that contains nitrogen, many of which are used in medicines (p.631)
allele / any of the alternative forms of a gene that occurs atr a specific place on a chromosome. (p181)
Allele / Any of several alternative forms of a gene. Allogenic Of the same species, but with a different genotype. Also allogeneic.
allele frequency / proportion of one allele, compared with all the alleles for that trait, in the gene pool. (p.328)
allergen / antigen that does not cause disease but still produces an immune response. (p.957)
allergy / immune response that oc curs when the body repsonds to a nondisease-causing antigen, such as pollen or animal dander (p.957)
alternations of generations / plant life cycle in which the plant alternates between haploid and diploid phases (p.664)
altruism / behavior in which an animal reducesits own fitness to help the other members of its social group (p.833)
alveolus / tiny,thin-walled structure across which oxygen gas is absorbed and carbon dioxide is released in the lungs (p.91)
Alzheimer's disease / A disease characterized by, among other things, progressive loss of memory. The development of Alzheimer's disease is thought to be associated, in part, with possessing certain alleles of the gene that encodes apolipoprotein E.
amino acid / molecule that makes up proteins, composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfer (p47)
Amino acids / Building blocks of proteins. There are 20 common amino acids: alanine, arginine, aspargine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine. Two more amino acids have been discovered in microbes: selenocysteine and pyrrolysine.
amniote / vertebrate whose embryo or fetus is enclosed by a thin, tough membranous sec. (p.778)
amniotic egg / waterproof container that allows an embryo to developeour of waterand externally from the mother without drying out (p.779)
amniotic sac / fluid-filled organ that cushions and protects the developing embryo of some vertebrates. (p. 1035)
amphibian / vertebrate that can live on land and in water. (p.773)
Amplification / The process of increasing the number of copies of a particular gene or chromosomal sequence.
Anaerobic / Growing in the absence of oxygen.
anaerobic / process that does not require oxygen to occur. (p. 113)
analogous / body part that is similar in function as a body part of another organism but is structurally different. (p. 313)
anaphase / third phase of mitosis durning which chromatids seperate and are pulled to opposite sides of the cell. (p. 140)
anaphylaxis / severe allergic reaction that causes airways to tighten and blood vessels to leak. (p. 958)
angiosperm / seed plant whose embryos are enclosed by fruit. (p 621)
anthropoid / humanlike primate. (p. 380)
Antibiotic / Chemical substance formed as a metabolic byproduct in bacteria or fungi and used to treat bacterial infections. Antibiotics can be produced naturally, using microorganisms, or synthetically.
antibiotic / chemical that kills or slows the growth of bacteria. (p. 564)
antibiotic resistance / process by which bacteria mutate so that they are no longer affected by an antibiotic. (p. 955)
Antibody / Protein produced by humans and higher animals in response to the presence of a specific antigen
antibody / protein produced by B cells that aids in the destruction of pathogens. (p. 947)
anticodon / set of three nucleotides in a tRNA molecule that binds to a complementary mRNA codon during translation. (p. 245)
Anticodon / Triplet of nucleotide bases (codon) in transfer RNA that pairs with (is complementary to) a triplet in messenger RNA. For example, if the codon is UCG, the anticodon is AGC. See also Base; Base pair; Complementarity.
antigen / protein marker that helps the immune system indentify foreign particals. (p. 951)
Antigen / A substance that, when introduced into the body, induces an immune response by a specific antibody. Antigenic determinant See Hapten.
Antihemophilic factors / A family of whole-blood proteins that initiate blood clotting. Some of these proteins, such as factor VIII, can be used to treat hemophilia. See also Factor VIII; Kidney plasminogen activator.
Antisense / A piece of DNA producing a mirror image ("antisense") messenger RNA that is opposite in sequence to one directing protein synthesis. Antisense technology is used to selectively turn off production of certain proteins.
antiseptic / chemical, such as soap, vinegar, or rubbing alcohol, that destroys pathogens outside of the body. (p. 145)
Antiserum / Blood serum containing specific antibodies against an antigen. Antisera are used to confer passive immunity to many diseases.
Apolipoprotein E (Apo E) / Certain alleles of the gene that encodes the protein apolipoprotein E have been associated with the development of heart disease and Alzheimer's disease.
apoptosis / programmedcell death. (p. 145)
appendage / extension, such as an antenna or arm, that is attatched to the body. (p. 730)
appendicular skeleton / part if the skeletal system that allows for most of the body's movements; includes bones of the arms, shoulders, legs, and pelvis. (p. 1000)
arachnid / terrestrialchelicerate, such as a spider. (p 740)
Archaea / one of the three domains of life, containing single celled prokaryotes in the kingdom Archaea. (p 534)
artery / large blood vessel that carries blood away from the heart. (p. 913)
arthropod / invertebrate with an exoskeleton, jointed appendages, and a segmented body. (p. 730)
artificial selection / process by which humans modify a species by breeding it for certain traits. (p 304)
asexual reproduction / process by which offspring are produces from a single parent; does not involve the joining of gametes. (p. 148)
Assay / Technique for measuring a biological response.
asthma / condition in which air pathways in the lungs constrict, making breathing difficult. (p. 916)
atmosphere / air blanketing Earth's solid surface. (p. 456)
atom / smallest basic unit of matter
ATP / see adenosene triphosphate (p. 100)
ATP synthase / enzyme that catalyzes the reaction that adds a high-energy phosphate group to ADP to form ATP (p. 110)
atrium / small chamber in the human heart that recieves blood from the veins (p. 917)
Attenuated Weakened / with reference to vaccines, made from pathogenic organisms that have been treated so as to render them avirulent.
Autoimmune disease / A disease in which the body produces antibodies against its own tissues.
Autoimmunity / A condition in which the body mounts an immune response against one of its own organs or tissues.
autonomic nervous system / division of the peripheral nervouse system that controls involuntary fuctions (p. 890)
autosome / chromosome that contains genes for characteristics not directly related to the sex of the organism (p. 169)
Autosome / Any chromosome other than a sex chromosome.
autotroph / organism that obtains its energy from abiotic sources such as sunlight or inorganic chemicals. (p. 406)
auxin / plant hormone that stimulates the lengthening of cells in the growing tip (p. 681)
Avirulent / Unable to cause disease.
axial skeleton / part of the skeletal system that supports the body's weigt and protects the body's internal tissues; includes the bones of the skull, spinal column, and rib cage. (p. 1001)
axon / longextenstion of the neuron membrane that carries impulses from one neuron to another page 876 of textbook.
B
Term / Definition
B cell / white blood cell that matures in the bone marrow and produces aintibodiees that fight off infection; also called b-lymphocyte (p.946)
B lymphocytes (B-cells) / A class of lymphocytes, released from the bone marrow, that produce antibodies.
Bacillus subtilis / A bacterium commonly used as a host in recombinant DNA experiments. Important because of its ability to secrete proteins.
Bacillus thuringiensis (Bt) / Naturally occurring soil bacterium that generates a protein toxic to a variety of lepidoptera, such as corn borers, but is harmless to people and animals.
Bacteria / one of the three domains of life, containing single celled prokaryotes in the kingdom bacteria (p.534)
Bacteriophage / virus that inbfects bacteria (p.228;549)
bacterium / organism that is within the kingdom bacteria (p.534)
Bacterium / Any of a large group of microscopic organisms with a very simple cell structure. Some manufacture their own food, some live as parasites on other organisms, and some live on decaying matter.
base / compound that accepts a proton when dissolved in solution (p.42)
Base / A key component of DNA and RNA molecules. Four different bases are found in DNA: adenine (A), cytosine (C), guanine (G) and thymine (T). In RNA, uracil (U) substitutes for thymine. Also known as nitrogenous bases. A base, a phosphate molecule and a sugar joined together constitute a nucleotide.
Base pair / Two nucleotide bases on different strands of the nucleic acid molecule that bond together. The bases can pair in only one way: adenine with thymine (DNA), or uracil (RNA) and guanine with cytosine.
base pairing rule / rule that describes how nucleotides form bonds in DNA; adenine (a) always bonds with thymine (t), and guanine (g) always bonds with cytosine (c). (p 232)
bathyal zone / zone of the ocean that extends from the edge of the neritic zone to the base of the continenal shelf. (p. 469)
behavorial isolation / isolation between populations due to differences in courtship or mating behavior. (p. 345)
benign / having no dangerous effect of health, especially referring to an abnormal growth of cells that are not cancerous (p. 146)
benthic zone / lake or pond bottom, where little t no sunlight can reach (p.474)
bilateral symmetry / body plan of some organsims in which the body can be divided equally along only one plane (p.701)
bile / fluid released by the liver and gallbladder intothe small intestine that aids in the digestion and absorptionof fats (p.980)
binary fission / assexual reproduction in which a cell divides into two equal parts (p. 148)
binomial comenclature / naming system in which each species is given a two-part scientific name using Latin words (p. 519)
Bioassay / Determination of the effectiveness of a compound by measuring its effect on animals, tissues or organisms in comparison with a standard preparation.
Bioaugmentation / Increasing the activity of bacteria that break down pollutants by adding more of their kind. A technique used in bioremediation.
Biocatalyst / In bioprocessing, an enzyme that activates or speeds up a biochemical reaction.
Biochemical / The product of a chemical reaction in a living organism.
Biochip / An electronic device that uses organic molecules to form a semiconductor.
Bioconversion / Chemical restructuring of raw materials by using a biocatalyst.
Biodegradable / Capable of being reduced to water and carbon dioxide by the action of microorganisms.
biodiversity / variety of life within an area (pp.5;403)
Bioenrichment / A bioremediation strategy that involves adding nutrients or oxygen, thereby bolstering the activity of microbes as they break down pollutants.
biogeochemical cyle / movement of a chemical through the biological and geological, or living and nonliving, parts of an ecosystem (p.413)
biogeography / study of the distribution of organisms around the world (p. 311)
bioinformatics / use of a computer databases to organize and analyze biological date (p. 282)
Bioinformatics / The science of informatics as applied to biological research. Informatics is the management and analysis of data using advanced computing techniques. Bioinformatics is particularly important as an adjunct to genomics research, because of the large amount of complex data this research generates.
Biolistic device / A device that shoots microscopic DNA coated particles into target cells.
Biologic / A therapeutic or prophylactic derived from a living source (human, animal or unicellular). Most biologics are complex mixtures that are not easily identified or characterized, and many are manufactured using biotechnology. Biological products often represent the cutting-edge of biomedical research and are sometimes the most effective way to prevent or treat a disease.
Biologic response modifier / A substance that alters the growth or functioning of a cell. Includes hormones and compounds that affect the nervous and immune systems.
biological clock / internal mechanism that controls an animal's activity patterns (p. 820)
Biological oxygen demand (BOD) / The amount of oxygen used for growth by organisms in water that contains organic matter.
biology / scientific study of all forms of life (p. 5)
biomagnification / condition of toxic substances being more concentrated in tissues of organisms igher of the food chain than ones lower in the food chain (p. 495)
Biomass / The totality of biological matter in a given area. As commonly used in biotechnology, refers to the use of cellulose, a renewable resource, for the production of chemicals that can be used to generate energy or as alternative feedstocks for the chemical industry to reduce dependence on nonrenewable fossil fuels.
biomass / total dry mass of all organisms in a given area (p.417)
Biomaterials / Biological molecules, such as proteins and complex sugars, used to make medical devices, including structural elements used in reconstructive surgery.
biome / regional or global community of organisms characterized by the climate conditions and plant communities that thrive there (p. 397)
Bioprocess / A process in which living cells, or components thereof, are used to produce a desired product. Bioreactor Vessel used for bioprocessing.
bioremdiation / process by which humans use living things to break down pollutants (p. 561)
Bioremediation / The use of microorganisms to remedy environmental problems, rendering hazardous wastes nonhazardous.
biosphere / all organisms and the part of Earth where they exist. (pp. 4;456)
Biosynthesis / Production of a chemical by a living organism.
biota / collection of living things (p. 456)
Biotechnology / The use of biological processes to solve problems or make useful products.
biotechnology / use and application of living thingws and biological processes (p.26)
biotic / living things, such as plants, animals, fungi, and bacteria (p.402)
biotic factors / living things or once living things, such as plants, animals, fungi and bacteria
Biotransformation / The use of enzymes in chemical synthesis to produce chemical compounds of a desired stereochemistry.
bipedal / animal that walks of two legs (p.381)
blade / broad part of a leaf where most of the photosynthesis of a plant takes place (p.652)
blastocyst / stage of development during which the zygote consists of a ball of cells (p. 1034)
Blastocyst (Blastula) / The 4- to 5-day-old ball of undifferentiated cells from which a prospective embryo develops. In mammals it consists of two distinct parts: the inner cell mass and the trophoblast.
blood pressure / force with which blood pushes against the wall of an artery (p. 923)
bond energy / amount of energy needed to break a bond between two particular atoms; or the amount of energy released when a bond forms between two particular atoms (p. 51)
book lung / respiratory organ that has several membranes that are arranged like the pages in a book (p. 740)
botany / study of plants (p. 629)
bottleneck effect / genetic drift that results from an event that drastically reduces the size ofa population (p. 336)
Bovine somatotropin (BST) / A hormone secreted by the bovine pituitary gland. It is used to increase milk production by improving the feed efficiency in dairy cattle milk. Also called bovine growth hormone.
brain stem / structure that connects the brain to the spinal cord and controls breathing and heartbeat (p. 888)
BRCA1 and BRCA2 (Breast Cancer genes 1 and 2) / Two genes that normally help to restrain cell growth, but which can contain certain genetic mutations associated with the development of breast and ovarian cancer. Note, however, that inherited BRCA1 and BRCA2 mutations are thought to account for less than 10 percent of all breast and ovarian cancers. Recent evidence suggests that somatic cell genetic mutations (i.e., noninherited genetic mutations) in these two genes may also play a role in the development of cancer.