Macrocytosis - Pathophysiology. 1  The most common cause of macrocytic anemia is megaloblastic anemia, which is the result of impaired DNA synthesis. 2  Vitamin B-12 and folate coenzymes are required for thymidylate and purine synthesis; thus, their deficiency results in retarded DNA synthesis.
(You may want to read the articles about Scales, the Major Scale, or Key Signatures first.) There are 12 different Major Scales: One with no sharps or flats, 4 with sharps, 4 with flats, and 3 with either sharps or flats depending upon enharmonic spelling. Major Scales with no sharps or flats: C Major. Major Scales with sharps: D, E, G, A. Major Scales with flats: E-flat, F, A-flat, B-flat.
A major/natural minor scale can never have both flats and sharps - it's either one or the other. The order of flats is the same as the order of sharps, but reversed. Every major scale that has a natural note as the tonic has sharps, except for C which has all natural notes and F, which has one flat. When a major scale has sharps, the last sharp (in the order of sharps) is the seventh note in the scale. Example: E major - the seventh note is D#. D# is the fourth sharp.