Quantitative Traits (p. 2), Photo by Peter Morenus/Courtesy of University of Connecticut; Reproductive Technology (p. 20), © R. Rawlins/Custom Medical Stock Photo; Reproductive Technology: Ethical Issues (p. 27), AP/Wide World Photos; Restriction Enzymes (p. 32), © Gabridge/Custom Medical Stock Photo; Ribosome (p. 43), © Dennis Kunkel/ Phototake; Rodent Models (p. 61), © Reuters NewMedia Inc./Corbis; Roundworm:
Caenorhabditis elegans (p. 63), © J. L. Carson/Custom Medical Stock Photo; Sanger, Fred (p. 65), © Bettmann/Corbis; Sequencing DNA (p. 74), © T. Bannor/Custom Medical Stock Photo; Severe Combined Immune Deficiency (p. 76), © Bettmann/Corbis; Tay-Sachs Disease (p. 100), © Dr. Charles J. Ball/ Corbis; Transgenic Animals (p. 125), Courtesy Cindy McKinney, Ph.D./Penn State University's Transgenic Mouse Facility; Transgenic Organisms: Ethical Issues (p. 131), © Daymon Hartley/Greenpeace; Transgenic Plants (p. 133), © Eurelios/Phototake; Transplantation (p. 140), © Reuters New Media/Corbis; Twins (p. 156), © Dennis Degnan/Corbis; X Chromosome (p. 175), © Gale Group; Yeast (p. 180), © Dennis Kunkel; Zebrafish (p. 182), Courtesy of Dr. Jordan Shin, Cardiovascular Research Center, Massachusetts General Hospital.
Glossary a the Greek letter alpha 3 the Greek letter beta y the Greek letter gamma A the Greek letter lambda a the Greek letter sigma E. coli the bacterium Escherichia coli "-ase" suffix indicating an enzyme acidic having the properties of an acid; the opposite of basic a, a acrosomal cap tip of sperm cell that contains digestive enzymes for penetrating the egg adenoma a tumor (cell mass) of gland cells aerobic with oxygen, or requiring it agar gel derived from algae agglutinate clump together aggregate stick together algorithm procedure or set of steps allele a particular form of a gene allelic variation presence of different gene forms (alleles) in a population allergen substance that triggers an allergic reaction allolactose "other lactose"; a modified form of lactose amino acid a building block of protein amino termini the ends of a protein chain with a free NH2 group amniocentesis removal of fluid from the amniotic sac surrounding a fetus, for diagnosis amplify produce many copies of, multiply anabolic steroids hormones used to build muscle mass anaerobic without oxygen or not requiring oxygen androgen testosterone or other masculinizing hormone anemia lack of oxygen-carrying capacity in the blood aneuploidy abnormal chromosome numbers angiogenesis growth of new blood vessels anion negatively charged ion anneal join together anode positive pole anterior front antibody immune-system protein that binds to foreign molecules antidiuretic a substance that prevents water loss antigen a foreign substance that provokes an immune response antigenicity ability to provoke an immune response apoptosis programmed cell death
Archaea one of three domains of life, a type of cell without a nucleus archaeans members of one of three domains of life, have types of cells without a nucleus aspirated removed with a needle and syringe aspiration inhalation of fluid or solids into the lungs association analysis estimation of the relationship between alleles or genotypes and disease asymptomatic without symptoms
ATP adenosine triphosphate, a high-energy compound used to power cell processes
ATPase an enzyme that breaks down ATP, releasing energy attenuation weaken or dilute atypical irregular autoimmune reaction of the immune system to the body's own tissues autoimmunity immune reaction to the body's own tissues autosomal describes a chromosome other than the X and Y sex-determining chromosomes autosome a chromosome that is not sex-determining (not X or Y) axon the long extension of a nerve cell down which information flows bacteriophage virus that infects bacteria basal lowest level
base pair two nucleotides (either DNA or RNA) linked by weak bonds basic having the properties of a base; opposite of acidic benign type of tumor that does not invade surrounding tissue binding protein protein that binds to another molecule, usually either DNA or protein biodiversity degree of variety of life bioinformatics use of information technology to analyze biological data biolistic firing a microscopic pellet into a biological sample (from biological/ ballistic)
biopolymers biological molecules formed from similar smaller molecules, such as DNA or protein biopsy removal of tissue sample for diagnosis biotechnology production of useful products bipolar disorder psychiatric disease characterized by alternating mania and depression blastocyst early stage of embryonic development brackish a mix of salt water and fresh water breeding analysis analysis of the offspring ratios in breeding experiments buffers substances that counteract rapid or wide pH changes in a solution Cajal Ramon y Cajal, Spanish neuroanatomist carcinogens substances that cause cancer carrier a person with one copy of a gene for a recessive trait, who therefore does not express the trait catalyst substance that speeds a reaction without being consumed (e.g., enzyme)
catalytic describes a substance that speeds a reaction without being consumed catalyze aid in the reaction of cathode negative pole cDNA complementary DNA
cell cycle sequence of growth, replication and division that produces new cells centenarian person who lives to age 100
centromere the region of the chromosome linking chromatids cerebrovascular related to the blood vessels in the brain cerebrovascular disease stroke, aneurysm, or other circulatory disorder affecting the brain charge density ratio of net charge on the protein to its molecular mass chemotaxi movement of a cell stimulated by a chemical attractant or repellent chemotherapeutic use of chemicals to kill cancer cells chloroplast the photosynthetic organelle of plants and algae chondrocyte a cell that forms cartilage chromatid a replicated chromosome before separation from its copy chromatin complex of DNA, histones, and other proteins, making up chromosomes ciliated protozoa single-celled organism possessing cilia, short hair-like extensions of the cell membrane circadian relating to day or day length cleavage hydrolysis cleave split clinical trials tests performed on human subjects codon a sequence of three mRNA nucleotides coding for one amino acid
Cold War prolonged U.S.-Soviet rivalry following World War II
colectomy colon removal colon crypts part of the large intestine complementary matching opposite, like hand and glove conformation three-dimensional shape congenital from birth conjugation a type of DNA exchange between bacteria cryo-electron microscope electron microscope that integrates multiple images to form a three-dimensional model of the sample cryopreservation use of very cold temperatures to preserve a sample cultivars plant varieties resulting from selective breeding cytochemist chemist specializing in cellular chemistry cytochemistry cellular chemistry cytogenetics study of chromosome structure and behavior cytologist a scientist who studies cells cytokine immune system signaling molecule cytokinesis division of the cell's cytoplasm cytology the study of cells cytoplasm the material in a cell, excluding the nucleus endangered in danger of extinction throughout all or a significant portion of a species' range endogenous derived from inside the organism endometriosis disorder of the endometrium, the lining of the uterus endometrium uterine lining endonuclease enzyme that cuts DNA or RNA within the chain endoplasmic reticulum network of membranes within the cell
cytosol fluid portion of a cell, not including the organelles de novo entirely new deleterious harmful dementia neurological illness characterized by impaired thought or awareness demography aspects of population structure, including size, age distribution, growth, and other factors denature destroy the structure of deoxynucleotide building block of DNA
dimerize linkage of two subunits dimorphism two forms diploid possessing pairs of chromosomes, one member of each pair derived from each parent disaccharide two sugar molecules linked together dizygotic fraternal or nonidentical DNA deoxyribonucleic acid domains regions dominant controlling the phenotype when one allele is present dopamine brain signaling chemical dosage compensation equalizing of expression level of X-chromosome genes between males and females, by silencing one X chromosome in females or amplifying expression in males ecosystem an ecological community and its environment ectopic expression expression of a gene in the wrong cells or tissues electrical gradient chemiosmotic gradient electrophoresis technique for separation of molecules based on size and charge eluting exiting embryogenesis development of the embryo from a fertilized egg ilS
endoscope tool used to see within the body endoscopic describes procedure wherein a tool is used to see within the body endosymbiosis symbiosis in which one partner lives within the other enzyme a protein that controls a reaction in a cell epidemiologic the spread of diseases in a population epidemiologists people who study the incidence and spread of diseases in a population epidemiology study of incidence and spread of diseases in a population epididymis tube above the testes for storage and maturation of sperm epigenetic not involving DNA sequence change epistasis suppression of a characteristic of one gene by the action of another gene epithelial cells one of four tissue types found in the body, characterized by thin sheets and usually serving a protective or secretory function
Escherichia coli common bacterium of the human gut, used in research as a model organism estrogen female horomone et al. "and others"
ethicists a person who writes and speaks about ethical issues etiology causation of disease, or the study of causation eubacteria one of three domains of life, comprising most groups previously classified as bacteria eugenics movement to "improve" the gene pool by selective breeding eukaryote organism with cells possessing a nucleus eukaryotic describing an organism that has cells containing nuclei ex vivo outside a living organism excise remove; cut out excision removal exogenous from outside exon coding region of genes exonuclease enzyme that cuts DNA or RNA at the end of a strand expression analysis whole-cell analysis of gene expression (use of a gene to create its RNA or protein product)
fallopian tubes tubes through which eggs pass to the uterus fermentation biochemical process of sugar breakdown without oxygen fibroblast undifferentiated cell normally giving rise to connective tissue cells fluorophore fluorescent molecule forensic related to legal proceedings founder population fractionated purified by separation based on chemical or physical properties fraternal twins dizygotic twins who share 50 percent of their genetic material frontal lobe one part of the forward section of the brain, responsible for planning, abstraction, and aspects of personality gamete reproductive cell, such as sperm or egg gastrulation embryonic stage at which primitive gut is formed gel electrophoresis technique for separation of molecules based on size and charge gene expression use of a gene to create the corresponding protein genetic code the relationship between RNA nucleotide triplets and the amino acids they cause to be added to a growing protein chain genetic drift evolutionary mechanism, involving random change in gene frequencies glycoprotein protein to which sugars are attached
Golgi network system in the cell for modifying, sorting, and delivering proteins gonads testes or ovaries gradient a difference in concentration between two regions
Gram negative bacteria bacteria that do not take up Gram stain, due to membrane structure ooooc genetic predisposition increased risk of developing diseases genome the total genetic material in a cell or organism genomics the study of gene sequences genotype set of genes present geothermal related to heat sources within Earth germ cell cell creating eggs or sperm germ-line cells giving rise to eggs or sperm gigabase one billion bases (of DNA) glucose sugar glycolipid molecule composed of sugar and fatty acid glycolysis the breakdown of the six-carbon carbohydrates glucose and fructose
Gram positive able to take up Gram stain, used to classify bacteria gynecomastia excessive breast development in males haploid possessing only one copy of each chromosome haplotype set of alleles or markers on a short chromosome segment hematopoiesis formation of the blood hematopoietic blood-forming heme iron-containing nitrogenous compound found in hemoglobin hemolysis breakdown of the blood cells hemolytic anemia blood disorder characterized by destruction of red blood cells hemophiliacs a person with hemophilia, a disorder of blood clotting herbivore plant eater heritability proportion of variability due to genes; ability to be inherited heritability estimates how much of what is observed is due to genetic factors heritable genetic heterochromatin condensed portion of chromosomes heterozygote an individual whose genetic information contains two different forms (alleles) of a particular gene heterozygous characterized by possession of two different forms (alleles) of a particular gene high-throughput rapid, with the capacity to analyze many samples in a short time histological related to tissues histology study of tissues histone protein around which DNA winds in the chromosome homeostasis maintenance of steady state within a living organism homologous carrying similar genes homologues chromosomes with corresponding genes that pair and exchange segments in meiosis homozygote an individual whose genetic information contains two identical copies of a particular gene homozygous containing two identical copies of a particular gene hormones molecules released by one cell to influence another hybrid combination of two different types hybridization (molecular) base-pairing among DNAs or RNAs of different origins hybridize to combine two different species hydrogen bond weak bond between the H of one molecule or group and a nitrogen or oxygen of another hydrolysis splitting with water hydrophilic "water-loving"
hydrophobic "water hating," such as oils hydrophobic interaction attraction between portions of a molecule (especially a protein) based on mutual repulsion of water hydroxyl group chemical group consisting of -OH
hyperplastic cell cell that is growing at an increased rate compared to normal cells, but is not yet cancerous hypogonadism underdeveloped testes or ovaries hypothalamus brain region that coordinates hormone and nervous systems hypothesis testable statement identical twins monozygotic twins who share 100 percent of their genetic material immunogenicity likelihood of triggering an immune system defense immunosuppression suppression of immune system function in vitro "in glass"; in lab apparatus, rather than within a living organism in vivo "in life"; in a living organism, rather than in a laboratory apparatus incubating heating to optimal temperature for growth informed consent knowledge of risks involved insecticide substance that kills insects interphase the time period between cell divisions intra-strand within a strand intravenous into a vein intron untranslated portion of a gene that interrupts coding regions karyotype the set of chromosomes in a cell, or a standard picture of the chromosomes kilobases units of measure of the length of a nucleicacid chain; one kilobase is equal to 1,000 base pairs kilodalton a unit of molecular weight, equal to the weight of 1000 hydrogen atoms kinase an enzyme that adds a phosphate group to another molecule, usually a protein ooooc immunosuppressive describes an agent able to suppress immune system function knocking out deleting of a gene or obstructing gene expression laparoscope surgical instrument that is inserted through a very small incision, usually guided by some type of imaging technique latent present or potential, but not apparent lesion damage ligand a molecule that binds to a receptor or other molecule ligase enzyme that repairs breaks in DNA ligate join together linkage analysis examination of co-inheritance of disease and DNA markers, used to locate disease genes lipid fat or wax-like molecule, insoluble in water loci/locus site(s) on a chromosome longitudinally lengthwise lumen the space within the tubes of the endoplasmic reticulum lymphocytes white blood cells lyse break apart lysis breakage macromolecular describes a large molecule, one composed of many similar parts macromolecule large molecule such as a protein, a carbohydrate, or a nucleic acid macrophage immune system cell that consumes foreign material and cellular debris malignancy cancerous tissue malignant cancerous; invasive tumor media (bacteria) nutrient source meiosis cell division that forms eggs or sperm melanocytes pigmented cells meta-analysis analysis of combined results from multiple clinical trials metabolism chemical reactions within a cell metabolite molecule involved in a metabolic pathway metaphase stage in mitosis at which chromosomes are aligned along the cell equator metastasis breaking away of cancerous cells from the initial tumor metastatic cancerous cells broken away from the initial tumor methylate add a methyl group to methylated a methyl group, CH3, added methylatior addition of a methyl group, CH3 microcephaly reduced head size microliters one thousandth of a milliliter micrometer 1/1000 meter microsatellites small repetitive DNA elements dispersed throughout the genome microtubule protein strands within the cell, part of the cytoskeleton miscegenation racial mixing mitochondria energy-producing cell organelle mitogen a substance that stimulates mitosis mitosis separation of replicated chromosomes molecular hybridization base-pairing among DNAs or RNAs of different origins molecular systematics the analysis of DNA and other molecules to determine evolutionary relationships monoclonal antibodies immune system proteins derived from a single B cell monosomy gamete that is missing a chromosome monozygotic genetically identical morphologically related to shape and form morphology related to shape and form mRNA messenger RNA mucoid having the properties of mucous mucosa outer covering designed to secrete mucus, often found lining cavities and internal surfaces mucous membranes nasal passages, gut lining, and other moist surfaces lining the body
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