Construction is the process of constructing a building or infrastructure. Construction differs from manufacturing in that manufacturing typically involves mass production of similar items without a designated purchaser, while construction typically takes place on location for a known client.
Eutherians, often called placental mammals, have a unique reproductive system in which unborn young are nourished for an extended period via a placenta. This system permits retention of the young in the protective environment of the uterus during most of early development.
Further information: Placenta. In placental mammals, the placenta forms after the embryo implants into the wall of the uterus. The developing fetus is connected to it via an umbilical cord. Animal placentas are classified based on the number of tissues separating the maternal from the fetal blood. The placentation types found in animals are: