DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.
You are watching a horror movie. The music changes to the familiar tune you recognize as a prelude to. danger. You tense up, your heart rate increases, your breathing becomes shallow, your mouth is dry.
1 Shortness of breath may be a sign of emphysema or heart disease. 2  Chest pain may signal angina pectoris caused by insufficient blood flow to the heart or a heart attack. 3  Difficulty swallowing, or persistent hoarseness, may signal a cancer in the mouth or larynx. 4  Painless bloody urination may signal bladder cancer.