If you're Rh-negative and your baby is Rh-positive, your body will react to the baby's blood as a foreign substance. Your body will create antibodies (proteins) against the baby's Rh-positive blood. These antibodies usually don't cause problems during a first pregnancy.
One point perspective definition. One-point perspective is a type of linear perspective. All categories of linear perspective include a horizon line and a stationary point (the position of the observer). In one-point perspective, only one vanishing point exists; lines radiate outwardly from this point, and perpendicular lines meet at this point. One-point perspective is the same as parallel perspective.
After its discovery, most artists only understood how to use one vanishing point near the center of their picture which then came to represent where everything is moving away from us. (right) Even when more vanishing points came into use later, this idea of it having a depth and distance-related function has persisted.