defense by prey species. The H-H fusion reaction is also exoergic, with a Q -value.7 1014 joule. That is to say, not all particles have the same energy. Yet, it is well known that two positively charged nuclei repel each other electrostaticallyi. Sinus, fold, hollow atrium, yard, court, hall nodus, knot Area of the vertebrate heart that initiates the heartbeat; located where the superior vena cava enters the right atrium; the pacemaker. Semilunar valve A valve located at the two exits of the heart, where the aorta leaves the left ventricle and the pulmonary artery leaves the right ventricle. Secondary growth The increase in girth of the stems and roots of many plants, especially woody, perennial dicots.
The possibilities are infinite. Structural formula A type of molecular notation in which the constituent atoms are joined by lines representing covalent bonds. Sink habitat A habitat where mortality exceeds reproduction.
Stele The central vascular cylinder in roots where xylem and phloem are located. Another chemical reaction might include silver ions (Ag). Secondary sex characteristics Characteristics of animals that distinguish between the two sexes but that do not produce or convey gametes; includes facial hair of the human male and enlarged hips and breasts of the female. Spectrophotometer An instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution. Sarx, the flesh lemma, husk, the specialized plasma membrane surrounding a muscle cell (muscle fiber capable of propagating action potentials. The machines employed to achieve these results include the Joint European Torus (JET) of the European Union, the Japanese Tokamak-60 (JT-60 and, until 1997, the Tokamak Fusion Test Reactor (tftr) in the United States. (2) Of organisms, having special adaptations to a particular habitat or mode of life.