The oxygen end of the molecule has a slight negative charge, and the hydrogen end has a slight positive charge. Adjacent water molecules are joined by ______ bonds. Relative to a pH of 6, a pH of 4 has a ______.
Maca redirects here. For other uses, see Maca (disambiguation). Lepidium meyenii (maca) is an herbaceous biennial plant of the crucifer family native to the high Andes of Peru. It was found at the Meseta de BombÃ³n close to Junin Lake in the Andes. It is grown for its fleshy hypocotyl (a fused hypocotyl and taproot), which is used as a root vegetable and a medicinal herb.
The CEA test may be used: 1  To monitor the treatment of people diagnosed with colon cancer. 2  It may also be used as a marker for medullary thyroid cancer and cancers of the rectum, lung, breast, liver, pancreas, stomach, and ovaries.3  An initial CEA test is typically ordered prior to treatment as a baseline value. An initial CEA test is typically ordered prior to treatment as a baseline value. 2  If the level is elevated, then the test can be used to monitor a person's response to therapy and to determine whether the cancer has progressed or recurred.