For most children, the National Heart, Lung, and Blood Institute recommends one cholesterol screening test between the ages of 9 and 11, and another cholesterol screening test between the ages of 17 and 21.
Wiktionary (0.00 / 0 votes) Rate this definition: fixation (Noun). The act of fixing, or the state of being fixed or fixated. fixation (Noun). The act of uniting chemically with a solid substance or in a solid form; reduction to a non-volatile condition; -- said of gaseous elements. fixation (Noun). The act or process of ceasing to be fluid and becoming firm.
define carbon fixation. The incorporation of carbon from atmospheric CO2 into the carbon in organic compounds. During photosynthesis in a C3 plant, carbon is fixed into a three carbon sugar as it enters the Calvin cycle. In C4 and CAM plants, carbon is fixed into a four carbon sugar.