Term | Definition |
-in | Suffix of a protein. |
-ose | Suffix of a sugar. |
10% rule | Only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed up to the levels of the food pyramid reduces as you go up |
5' cap | The 5' end of a pre-mRNA molecule modified by the addition of a cap of guanine nucleotide. |
abdominal cavity | Cavity housing intestines. |
abiotic factors . | Nonliving components of environment |
abscisic acid (ABA) | A plant hormone that slows down growth, promotes seed dormancy and facilitates drought tolerance. |
absorption spectrum | A graph plotting a pigment light light absorption. |
acclimatization | Adjusting to a new range of environmental temperatures. |
acetyl-CoA | Is formed when pyruvate first enters into the mitochondria via active transport. |
acetylcholine | Common vertebrate neurotransmitter, especially in neuromuscular junctions. |
acquired immunity | Immunity that is present only after exposure and is highly specific. |
Acquired Immunodeficiency Syndrome (AIDS) | The most advanced, and fatal, stage of an HIV infection. |
action potential | A neural impulse; a brief electrical charge that travels down an axon. |
action spectrum | A profile of the relative performance of the different wavelengths in photosynthesis. |
activation energy | The amount of energy needed to push the reactants over an energy barrier. |
activator | A protein that binds to DNA and stimulates transcription of a specific gene. |
active immunity | A form of acquired immunity in which the body produces its own antibodies against disease-causing antigens. |
active site | A pocket or groove on the surface of the enzyme. |
active transport | When a cell gets materials or excretes them by using its own energy, usually through ATP; going against a concentration gradient. |
actual evapotranspiration | Annual amount of water transpired by plants and evaporated from landscape. |
actual range | Area an organism actually occupies. |
adaptive radiation | Evolution of many new species from a common ancestor as a result of introduction to new environments. |
addition rule | Considering mutually exclusive events, the probability of both occurring is the sum of the probabilities of each event. |
adenylyl cyclase | Converts ATP to cyclic AMP in response to an extracellular signal. |
adhesion | Water molecules sticking to other surfaces. |
adipose tissue | Tissue that stores fat. |
age structure | Relative number of individuals at each age. |
aggregate fruit | A fruit derived from a single flower that has more than one carpel. |
agonistic behavior | Competition that determines who wins a prize, such as food or mates. |
alcohol fermentation | When pyruvate is converted to ethanol in 2 steps. |
allele | One of the alternative forms of a gene that governs a characteristic, such as hair color. |
allele frequency | Proportion of an allele in a gene pool. |
allometric growth | Proportioning that gives a body a specific form. |
allopatric speciation | When a population is divided; leads to speciation. |
allopolyploid | Sterile hybrid is changed to a fertile polyploid due to mutation; fertile with each other, but not parent species. |
allosteric regulation | When a protein's function at one site is affected by the binding of a regulatory molecule to a separate site. |
alpha glucose | Monomer for starch and glycogen. |
alteration of generations | The alteration of two or more different forms in the life cycle of a plant or animal. |
alternative RNA splicing | Genes giving rise to two or more different polypeptides depending upon which segments are treated as exons. |
altruism | Behavior that benefits another without benefiting oneself. |
aminocentesis | Prenatal diagnostic technique that involves inserting a needle to obtain a sample of amniotic fluid that surrounds the fetus. |
amphipathic | Molecules are said to be this when it has regions that are both hydrophilic and hydrophobic. |
anabolic pathways | Metabolic pathways that consume energy to build complicated molecules from simpler ones. |
anabolism | Metabolic pathways that construct molecules, requiring energy. |
anaerobic | Occurs by fermentation, which generate ATP solely by substrate-level phosphorylation. |
analogy | Anatomical similarity due to convergent evolution. |
anaphylactic shock | A severe reaction that occurs when an allergen is introduced to the bloodstream of an allergic individual. Characterized by bronchoconstriction, labored breathing, widespread vasodilation, circulatory shock, and sometimes sudden death. |
anatomy | Study of the structure of an organism. |
aneuploidy | Abnormal number of chromosomes. |
anther | In an angiosperm, the terminal pollen sac of a stamen, where pollen grains containing sperm-producing male gametophytes form. |
antibiotic resistance | Resistance evolving rapidly in many species of prokaryotes due to overuse of antibiotics, especially in agriculture. |
antibiotics | Interfere with production of peptidoglycan; harm bacteria but not eukaryotes. |
antibodies | Protein that is produced by lymphocytes and that attaches to a specific antigen. |
anticodon | Specialized base triplet at one end of a tRNA molecule that recognizes a particular complementary codon on an mRNA molecule. |
antigen | Any foreign molecule that is specifically recognized by lymphocytes and elicits an immune response. |
apoptosis | Programmed cell death. |
aposematic coloration | Bright warning colors in animals with a chemical defense. |
aquaporin | A membrane protein, specifically a transport protein, that facilitates the passage of water through channel proteins. |
archaea | Domain of unicellular prokaryotes that have cell walls lacking peptidoglycan. Like eukaryotes, DNA contains histone proteins. |
artificial selection | Humans modifying species for desired traits through selective breeding. |
asexual reproduction | One parent produces a genetically identical offspring by mitosis. |
associative learning | The ability of animals to associate one feature with another. |
asters | Microtubules and fibers that radiate out from the centrioles. |
astrocytes | Provide structural and metabolic support for neurons. |
ATP (adenosine triphosphate) | Composed of a sugar ribose, nitrogenous base adenine, and a chain of three phosphate groups bonded to it. |
ATP synthase | The enzyme that make ATP from ADPand inorganic phosphate. |
autoimmune diseases | Diseases caused when the immune system loses tolerance for self and turns against certain molecules in the body. |
autonomic nervous system | The part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands. |
autopolyploid | Having more than two sets of chromosomes from a single species. |
autosomes | Chromosomes that are not directly involved in determining the sex of an individual. |
auxin Indoleacetic acid (IAA) | a natural plant hormone that has a variety of effects, including cell elongation, root formation, secondary growth, and fruit growth. |
avirulent | A term describing a pathogen that can only mildly harm, but not kill, the host plant. |
axon | Long nerve fiber that conducts away from the cell body of the neuron. |
axon hillock | Cone shaped region of an axon where it joins the cell body. |
B cell receptor | The antigen receptor on B cells: a Y-Shaped, membrane-bound molecule consisting of two identical heavy chains and two identical light chains linked by disulfide bridges and containing two antigen-binding sites. |
B lymphocytes (B cells) | Lymphocyte that matures in the bone marrow and secretes antibodies. |
bacilli | Rod-shaped bacteria. |
bacterial artificial chromosome (BAC) | An artificial version of a bacterial chromosome that can carry inserts of 100, 000 to 500, 000 base pairs. |
bacteriophage | A virus that infects bacteria; also called a phage. |
barr body | A dense body formed from a deactivated X chromosome. |
basal metabolic rate (BMR) | The metabolic rate of a nongrowing, resting, fasting, nonstressed endotherm. |
basement membrane | Cells at the base of an epithelial layer are attached to this. |
Batesian mimicry | Species mimics the appearance of an unpalatable or harmful. |
behavior | The way an organism reacts to changes in its internal condition or external environment. |
behavioral isolation | Incompatible courtship rituals, pheromones, or bird songs. |
beta glucose. | Monomer for cellulose and chitin |
big-bang reproduction | Species that have only a single reproductive opportunity, such as agave and salmon. |
binary fission | A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size. |
bioenergetics | Flow of energy through an animal. Limits its behavior, growth, reproduction. |
biogeographic realms | Broad patterns of distribution due to continental drift and barriers such as deserts and mountain ranges. |
biogeography | Geographic distribution of species. |
biological augmentation | Uses organisms to add essential materials to degraded ecosystems. |
biological clock | An innate mechanism in living organisms that controls the periodicity of many physiological functions. |
biological magnification | Toxins become more concentrated in successive trophic levels. |
biological species concept | Species is a group of populations whose members have the potential to produce fertile offspring. |
biomanipulation | Technique for restoring eutrophic lakes that reduces populations of algae by manipulating higher-level consumers. |
biomass | Total dry mass of all individuals in a population. |
biome | Major types of ecological association that occupy broad geographic regions. |
bionomial nomenclature | Scientific name. |
bioremediation | Use of living organisms such as prokaryotes, fungi, or plants to detoxify polluted ecosystems. |
biosphere | The sum of all ecosystems. |
biota | Biotic factors. |
biotechnology | The manipulation of living organisms or their components to produce useful products. |
biotic factors | All the plant and animal life of a particular region. |
blood | Connective tissue made of plasma, erythrocytes, leukocytes, and platelets. |
blue-light photoreceptors | A class of light receptors in plants. Blue light initiates a variety of responses, such as phototropism and slowing of hypocotyl elongation. |
bone | Mineralized connective tissue. |
bottleneck effect | When a population has been dramatically reduced, and the gene pool is no longer reflective of the original population's. |
bottom-up model | Unidirectional influence from lower to higher trophic levels. (V --> H) |
brainstem | The oldest part and central core of the brain, responsible for automatic survival functions. |
brown fat | Tissue in neck and between shoulders of some mammals that is specialized for rapid heat production. |
calvin cycle | Carbon fixation process in photosynthesis. Forms sugar and other organic compounds. |
cancer | Any malignant growth or tumor caused by abnormal and uncontrolled cell division. |
capsid | The protein shell that encloses a viral genome. It may be rod-shaped, polyhedral, or more complex in shape. |
capsule | Covers the cell wall in prokaryotes. |
carbon fixation | The initial incorporation of carbon into organic compounds. |
cardiac muscle | Muscle that is branched, striated, singe nucleated. |
carotenoids | Accessory pigments that broaden the spectrum of colors that can drive photosynthesis. |
carpel | The ovule-producing reproductive organ of a flower, consisting of the stigma, style, and ovary. |
carrier protein | A membrane protein, specifically a transport protein, that holds onto molecules and changes their shapes in a way that shuttles them across the membrane. |
carrying capacity (K) | Maximum population size that a particular environment can support. |
cartilage | Made of collagenous fibers in matrix of chondroitin sulfate. |
catabolic pathways | Metabolic pathways that release energy by breaking down complex molecules into simpler compounds. |
catabolism | Metabolic pathways that break down molecules, releasing energy. |
catalyst | A chemical agent that speeds up a reaction without being consumed by the reaction. |
Cdk | Complex of cyclin and kinase. |
cDNA library | A limited gene library using complementary DNA. The library includes only the genes that were transcribed in the cells examined. |
cell body | Contains most of a neuron's organelles and its nucleus. |
cell cycle | Series of events that cells go through as they grow and divide. |
cell differentiation | Cell specialization in structure and function. |
cell differentiation | the process by which a cell becomes specialized for a specific structure or function. |
cell division | The process in reproduction and growth by which a cell divides to form daughter cells. |
cell plate | A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis. |
cell wall | Strong layer around the cell membrane in plants, algae, and some bacteria. |
cell-cell recognition | The function of membrane proteins in which some glycoproteins serve as ID tags that are recognized by membrane proteins of other cells. |
cell-mediated immune response | The branch of acquired immunity that involves the activation of cytotoxic T cells, which defend against infected cells. |
cellular respiration | When oxygen is consumed as a reactant along with the organic fuel. |
cellulose | Carbohydrate component of plant cell walls. |
Central Nervous System (CNS) | Includes the brain and spinal cord. |
centriole | In animal cells, a cytoplasmic organelle that organizes the mitotic spindle fibers during cell reproductions. |
centromere | The region of the chromosome that holds the two sister chromatids together during mitosis. |
centrosome | A structure in animal cells containing centrioles from which the spindle fibers develop. |
cerebellum | The "little brain" attached to the rear of the brainstem; it helps coordinate voluntary movement and balance. |
cerebral cortex | Interconnected neural cells that covers the cerebral hemispheres; the body's ultimate control and information-processing center. |
cerebral hemispheres | The right and left halves of the cerebrum. |