GLOSSARY 



A adenosine. 



Acetabularia a large unicelkilar marine alga which is differentiated into a 

 rhizoid, a stem, and a cap. 



ACTH a hormone from the anterior pituitary gland which stimulates the 

 adrenal cortex. 



actinomoiphic regular-shaped flowers with radial symmetry. 



activity the ideal or thermodynamic concentration of a substance, the sub- 

 stitution of which for the true concentration permits the application 

 of the law of mass action. 



alleles the alternative forms of hereditary material that may exist at the 

 same locus. 



analogue a chemical that resembles another in structure or function. 



androecium the stamens of a flower. 



aneuploid an organism with a chromosome number which is not an exact 

 multiple of the haploid number. Types such as 2N + 1 or 2N — 2 are 

 aneuploid. 



angiosperm plants with true flowers which produce seeds enclosed within 

 an ovary. 



Angstrom unit 10"'* centimeter. 



anisotropic exhibiting different properties in different directions. 



antimetabolite a compound which interferes with utilization of a normal 

 metabolic intermediate. 



Arabidopsis a plant. 



archaeopteryx an extinct bird which possessed teeth. 



archencephalon primitive brain anterior to the end of the notochord. 



ascospore a spore developing in an ascus, or sac. 



assimilatory capable of being incorporated into the complex of living ma- 

 terial. 



atherosclerosis fatt\' degeneration of the connective tissue of the arterial 

 walls. 



ATHF allotetrahydrocortisol, a Cortisol metabolite. 



atropine an alkaloid drug which inhibits structures innervated by post- 

 ganglionic cholinergic nerves. 



autogenic succession due to biotic reaction; contrasts with allogenic suc- 

 cession. 



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