adventitious roots Roots that develop from the stem following the death of the primary root. Branches from the adventitious roots form a fibrous root system in which all roots are about the same size; occur in monocots . age structure The relative proportion of individuals in each age group in a population. aggregates Fairly random associations of animals with little or no internal organization; form in response to a single stimulus and disperse when the stimulus is removed; one of the three broad classes of social organization. albinism Genetic condition caused by the body's inability to manufacture pigments; an autosomal recessive trait. aldosterone A hormone secreted by the adrenal glands that controls the reabsorption of sodium in the renal tubule of the nephron . alleles Alternate forms of a gene . allergens Antigens that provoke an allergic reaction. alpha decay Type of radioactive decay in which a radioisotope emits a large but slow-moving particle consisting of two protons and two neutrons. alternation of generations
This is the end of the preview. Sign up
access the rest of the document.