DNA Deoxyribonucleic acid. See nucleic acid . The property of one of a pair of alleles or traits that suppresses expression of the other in the heterozygous condition. An inherited disorder resulting in abnormal forearms or hands. Dopamine A precursor of noradrenaline, a hormone responsible for transmission in the sympathetic nervous system and in some parts of the central nervous system .
Dopamine occurs especially as a neurotransmitter in the brain.
Dorsal root ganglia Swellings on the dorsal roots of spinal nerves . Dose-response curve A graph to show the relation between the dose of a foreign substance and the degree of response it produces, as measured by the percentage of the exposed population showing a defined effect. The molecular structure of DNA , in which two strands of DNA, joined together by a base pairing, coil around one another. See Figure 1.1. Downer cows Refers to the clinical manifestation of being unable to rise.