In humans, the placenta is essential to the embryo for RESPIRATION, NUTRITION AND EXCRETION.
The placenta refers to an organ in the uterus of pregnant mammals that is responsible for nourishing and maintaining the unborn baby through the umbilical cord. Th placenta has many functions but primarily it plays critical roles in the nutrition, respiration and excretion of the fetus. Its other functions include: production of hormones, production of immunity for the fetus for prevention from infections, etc. <span />
Sea floor sediment provide an invaluable key to past climate change. Finely varved sediments from areas of rapid deposition provide a high-resolution record of past climate variation, and volcanic ash layers contribute to the comprehensive study of climate change on relatively short timescales. Oceanographers like to say that we know more about the dark side of the Moon than we do about the oceans. That statement is doubly true of the seafloor. Although modern technology has allowed us to learn more about the seafloor, vast regions remain unexplored. Scuba divers can only dive to about 40 meters and they cannot stay down there for very long. Although this is good for researching the organisms and ecosystems very near a coast, most oceanic research requires accessing greater depths.
Economics - is the social science that describes the factors that determine the production, distribution and consumption of goods and services