The main function of the right side of the human heart <span> receives de-oxygenated blood from the body tissues (from the upper- and lower-body via the superior vena cava and the inferior vena cava, respectively) into the </span>right<span> atrium. This de-oxygenated blood passes through the tricuspid valve into the </span>right<span>ventricle</span>
DDT was one of the first chemicals in widespread use as a pesticide. Following World War II, it was promoted as a wonder-chemical, the simple solution to pest problems large and small. Today, nearly 40 years after DDT was banned in the U.S., we continue to live with its long-lasting effects:
1. Species vary over time
2. The fossil and the living species will have some similarities and some differences
