Biology Glossary

Biology Glossary

Abiogenesis … a hypothetical organic phenomenon by which living organisms are created from nonliving matter.

Acid … any of various water-soluble compounds having a sour taste and capable of turning litmus red and reacting with a base to form a salt.

Activation Energy … the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur.

Active Site … The specific portion of an enzyme that attaches to the substrate by means of weak chemical bonds.

Active Transport … transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient.

Adoption … a legal proceeding that creates a parent-child relation between persons not related by blood.

Aerobic … process that requires oxygen.

Amino Acid … monomer that makes up proteins; contains carboxyl and amino functional groups.

Anarobic … metabolic process that does not require oxygen.

Aristotle … Greek philosopher. A pupil of Plato, the tutor of Alexander the Great, and the author of works on logic, metaphysics, ethics, natural sciences, politics, and poetics, he profoundly influenced Western thought. In his philosophical system, which led him to criticize what he saw as Plato’s metaphysical excesses, theory follows empirical observation and logic, based on the syllogism, is the essential method of rational inquiry.

Artificial Selection … selection by humans for breeding of useful traits from the natural variation among different organisms.

Atom … (physics and chemistry) the smallest component of an element having the chemical properties of the element.

ATP … (adenosine triphosphate) main energy source that cells use for most of their work.

Autosomes … chromosomes that are not directly involved in determining the sex of an individual.

Autotroph … organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer.

Base … any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water.

Biogenesis … the production of living organisms from other living organisms.

Biotechnology … the branch of molecular biology that studies the use of microorganisms to perform specific industrial processes.

Buffer … an implement consisting of soft material mounted on a block, weak acid or base that can react with strong acids or bases to help prevent sharp, sudden changes in pH.

Carbohydrate … compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body.

Cell … a small unit serving as part of or as the nucleus of a larger political movement, the basic structural and functional unit of all organisms.

Cell Hierarchy … Cells >> Tissue >> organs >> organ systems >> organisms.

Cell Membrane … thin, flexible barrier around a cell, regulates what enters and leaves the cell.

Cell Wall … a thin membrane around the cytoplasm of a cell.

Cellular Respiration … the metabolic processes whereby certain organisms obtain energy from organic moelcules.

Charles Darwin … English naturalist. He studied the plants and animals of South America and the Pacific islands, and in his book On the Origin of Species by Means of Natural Selection (1859) set forth his theory of evolution. (p. 715).

Charles Drew … an African American doctor who successful separated blood plasma which later was used in creating blood banks.

Chemical Reaction … (chemistry) a process in which one or more substances are changed into others.

Chlorophyll … green pigment in plants that absorbs light energy used to carry out photosynthesis.

Chloroplast … plastid containing chlorophyll and other pigments.

Chromosomes … thread like structures that have genetic info that is passed down from one generation to the next.

Circulation … free movement or passage through a series of vessels (as of water through pipes or sap through a plant).

Classification … The division of organisms into groups, or classes, based on specific characteristics.

Cloning … a general term for the research activity that creates a copy of some biological entity (a gene or organism or cell).

Coevolution … the process in which species exert selective pressure on each other and gradually evolve new features or behaviors as a result of those pressures.

Color Blind … genetic disorder in which people are blind to green or red.

Concentration Gradient … a difference in the concentration of a substance across a distance.

Covalent … A compound where atoms are shared.

Cytokinesis … The final stage of the cell cycle, in which the cell’s cytoplasm divides, distributing the organelles into each of the two new cells.

Cytoplasm … a jellylike fluid inside the cell in which the organelles are suspended.

Develop … come to have or undergo a change of (physical features and attributes).

Diffusion … process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated.

Digestion … the organic process by which food is converted into substances that can be absorbed into the body.

Dihybrid … An organism that is heterozygous with respect to two genes of interest. A dihybrid results from a cross between parents doubly homozygous for different alleles. For example, parents of genotype AABB and aabb produce a dihybrid of genotype AaBb.

Diploid … (genetics) an organism or cell having two sets of chromosomes or twice the haploid number.

DNA … (biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helixdeoxyribonucleic acid, the material that contains the information that determines inherited characteristics.

DNA Replication … process by which DNA is copied in a cell before a cell divides by mitosis, meiosis, or binary fission.

Down Syndrome … A human genetic disease resulting from having an extra chromosome 21, characterized by mental retardation and heart and respiratory defects.

Element … a pure substance made of only one kind of atom.

Endoplasmic Reticulum … a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.

Endothermic Reaction … a chemical reaction accompanied by the absorption of heat.

Enzyme … any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions.

Equilibrium … a chemical reaction and its reverse proceed at equal rates.

Ethyl Alcohol … nonflavored alcohol of 95 percent or 190 proof used for blending with straight whiskies and in making gin and liqueurs.

Eukaryote … an organism with cells characteristic of all life forms except primitive microorganisms such as bacteria.

Evolution … (biology) the sequence of events involved in the evolutionary development of a species or taxonomic group of organisms.

Excretion … the process by which wastes are removed from the body.

Exothermic Reaction … a chemical reaction accompanied by the evolution of heat.

Extinction … a conditioning process in which the reinforcer is removed and a conditioned response becomes independent of the conditioned stimulus.

Facilitated Diffusion … movement of specific molecules across cell membranes through protein channels.

Fitness … ability of an organism to survive and reproduce in its environment.

Fossil … the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil.

Gene Expression … conversion of the information encoded in a gene first into messenger RNA and then to a protein.

Gene Regulation … regulation of transcription; controlled by an operon which varies the accessibility of the RNA polymerase to genes being transcribed.

Genetic Code … the rule that describes how a sequence of nucleotides, read in groups of three consecutive nucleotides (triplets) that correspond to specific amino acids, specifies the amino acid sequence of a protein.

Genetic Engineering … the technology of preparing recombinant DNA in vitro by cutting up DNA molecules and splicing together fragments from more than one organism.

Genus … (biology) taxonomic group containing one or more species.

Glycolysis … a metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and release energy for the body in the form of ATP.

Golgi Apparatus … a net-like structure in the cytoplasm of animal cells (especially in those cells that produce secretions).

Gregory Mendel … established the patterns of heredity.

Growth … (biology) the process of an individual organism growing organically.

Heredity … the biological process whereby genetic factors are transmitted from one generation to the next.

Heterotrophy … organisms that cannot make their own food and must feed on other organisms for energy and nutrients.

Homeostasis … metabolic equilibrium actively maintained by several complex biological mechanisms that operate via the autonomic nervous system to offset disrupting changes.

Homologous … corresponding or similar in position or structure or function or characteristics.

Human Genome Project … An international collaborative effort to map and sequence the DNA of the entire human genome.

Hydrogen Bonds … attractive forces in which a hydrogen covalently bonded to a very electronegative atom is also weakly bonded to an unshared electron pair of another electronegative atom.

Hypertonic … (of a solution) having a higher osmotic pressure than a comparison solution.

Hypotonic … (of a solution) having a lower osmotic pressure than a comparison solution.

Isotonic … (used of solutions) having the same or equal osmotic pressure.

Lactic Acid … Produced in muscle cells from the reduction of pyruvate (under anaerobic conditions) to regenerate NAD+ so that glycolysis can continue. A rise in lactic acid usually accompanies an increase in physical activity.

Linnaeus … Swedish botanist who proposed the modern system of biological nomenclature (1707-1778).

Lipid … macromolecule made mainly from carbon and hydrogen atoms; includes fats, oils, and waxes.

Lysosome … an organelle found in the cytoplasm of most cells (especially in leukocytes and liver and kidney cells).

Meiosis … (genetics) cell division that produces reproductive cells in sexually reproducing organisms.

Metabolism … the organic processes (in a cell or organism) that are necessary for life.

Mitochondria … powerhouse of the cell, produces energy (ATP) from oxygen and sugar(Cellular respiration).

Mitosis … in eukaryotic cells, a process of cell division that forms two new nuclei, each of which has the same number of chromosomes.

Monohybrid … a hybrid produced by crossing parents that are homozygous except for a single gene locus that has two alleles (as in Mendel’s experiments with garden peas).

MRNA … messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome.

Multicellular … consisting of many cells.

Mutagens … agents, such as chemicals or radiation, that damage or alter genetic material (DNA) in cells.

Mutation … (biology) an organism that has characteristics resulting from chromosomal alteration.

Natural Selection … process by which individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest.

Nucleic Acid … an organic compound, either RNA or DNA, whose molecules are made up of one or two chains of nucleotides and carry genetic information.

Nucleotide … monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base.

Nucleus … a part of the cell containing DNA and RNA and responsible for growth and reproduction.

Nutrition … (physiology) the organic process of nourishing or being nourished.

Operons … in prokaryotes, a set of genes, often encoding the proteins needed for a complete metabolic pathway, including both the structural genes and a common promoter and operator that control transcription of the structural genes.

Organ … (music) an electronic simulation of a pipe organ, a fully differentiated structural and functional unit in an animal that is specialized for some particular function.

Organ System … group of organs that work together to perform a specific function.

Organelle … specialized structure that performs important cellular functions within a eukaryotic cell.

Osmosis … diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal.

Passive Transport … the movement of substances across a cell membrane without the use of energy by the cell.

Pastuer … the scientist that finally disproved spontaneous generation.

Pedigree … a diagram that shows the occurrence of a genetic trait in several generations of a family.

pH … (chemistry) p(otential of) H(ydrogen), a value that indicated the acidity or alkalinity of a solution on a scale of 0-14, based on the proportion of H+ ions.

Photosynthesis … process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches.

Phylogeny … (biology) the sequence of events involved in the evolutionary development of a species or taxonomic group of organisms.

Plasmid … a small cellular inclusion consisting of a ring of DNA that is not in a chromosome but is capable of autonomous replication.

Plastid … any of various small particles in the cytoplasm of the cells of plants and some animals containing pigments or starch or oil or protein.

Product … a chemical substance formed as a result of a chemical reaction.

Prokaryote … a unicellular organism having cells lacking membrane-bound nuclei.

Protein … macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair and to make up enzymes.

Punnett Square … a chart that shows all the possible combinations of alleles that can result from a genetic cross.

Reactant … a chemical substance that is present at the start of a chemical reaction.

Recombinant DNA … genetically engineered DNA made by recombining fragments of DNA from different organisms.

Red 1 … Once hydrogen in core is all fused. Still fusion of hydrogen in shell. No longer fuel in core to provide energy and pressure to balance gravity. Core shrinks, pressure goes up, temp goes up, until the later of H outside the core becomes hot enough to fuse H into He. Temperature then rises rapidly in H burning shell which expands dramatically.

Regulation … (embryology) the ability of an early embryo to continue normal development after its structure has been somehow damaged or altered.

Relative Dating … method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock.

Reproduction … recall that is hypothesized to work by storing the original stimulus input and reproducing it during recall, The process by which organisms make more of their own kind from one generation to the next.

Respiration … the metabolic processes whereby certain organisms obtain energy from organic moelcules.

Ribosome … an organelle in the cytoplasm of a living cell, small particle in the cell on which proteins are assembled; made of RNA and protein.

RNA … (biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes.

RRNA … ribosomal RNA; type of RNA that makes up part of the ribosome.

Semipermeable … characteristic of a cell membrane which allows some molecules to pass through but not others.

Species … (biology) taxonomic group whose members can interbreed.

Stem Cell … an undifferentiated cell whose daughter cells may differentiate into other cell types (such as blood cells).

Substrate … reactant of an enzyme-catalyzed reaction.

Synthesis … the process of producing a chemical compound (usually by the union of simpler chemical compounds).

Taxonomy … (biology) study of the general principles of scientific classification.

Tissue … a part of an organism consisting of an aggregate of cells having a similar structure and function.

Transcription … (genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA.

Transgenic … organism whose genome has been altered to contain one or more genes from another organism or species.

Translation … (genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm.

TRNA … short-chain RNA molecules present in the cell (in at least 20 varieties, each variety capable of combining with a specific amino acid) that attach the correct amino acid to the protein chain that is being synthesized at the ribosome of the cell (according.

Unicellular … having or consisting of a single cell.

Vacuole … a tiny cavity filled with fluid in the cytoplasm of a cell.

Vestigial … not fully developed in mature animals.