biology-dictionary_11-06-2009

Behavioral ecology A heuristic approach based on the expectation that Darwinian fitness (reproductive success) is improved by op ...

Bioenergetics The study of how organisms manage their energy resources. Biogeochemical cycles The various nutrient circuits, whi ...

Bisexual Having both male and female reproductive organs; hermaphroditic. Biting Causing a stinging sensation; nipping: biting c ...

Blood-brain barrier A specialized capillary arrangement in the brain that restricts the passage of most substances into the brai ...

Bowman's capsule A cup-shaped receptacle in the vertebrate kidney that is the initial, expanded segment of the nephron where fil ...

Buffer A substance that consists of acid and base forms in solution and that minimizes changes in pH when extraneous acids or ba ...

C 4 pathway The set of reactions by which some plants initially fix carbon in the four-carbon compound oxaloacetic acid; the car ...

Calyx Collectively, the sepals of a flower. CAM photosynthesis Crassulacean acid metabolism, also known as CAM photosynthesis, i ...

Capsid The protein shell that encloses the viral genome; rod-shaped, polyhedral, or more completely shaped. Capsule A slimy laye ...

Carcinogen A chemical agent that causes cancer. Cardiac muscle A type of muscle that forms the contractile wall of the heart; it ...

Casparian strip A water-impermeable ring of wax around endodermal cells in plants that blocks the passive flow of water and solu ...

Cell cycle An ordered sequence of events in the life of a dividing eukaryotic cell, composed of the M, G 1 , S, and G 2 phases. ...

Cell wall A protective layer external to the plasma membrane in plant cells, bacteria, fungi, and some protists. In the case of ...

Centriole A structure in an animal cell, composed of cylinders of microtubule triplets arranged in a 9 + 0 pattern. An animal ce ...

Chaparral A scrubland biome of dense, spiny evergreen shrubs found at midlatitudes along coasts where cold ocean currents circul ...

Chemoheterotroph An organism that must consume organic molecules for both energy and carbon. Chemoreceptor A receptor that trans ...

Cholesterol A steroid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthe ...

Chromosome map A diagram of the linear order of the genes on a chromosome. Chromatophores A pigment-containing or pigment-produc ...

Cladophylls A photosynthetic branch or portion of a stem that resembles and functions as a leaf, as in the asparagus. Also calle ...

Clonal selection The mechanism that determines specificity and accounts for antigen memory in the immune system; occurs because ...