The embryonic development occurs through the different developmental stages like cleavage, morula, blastula and so on. The formation of the germ layers occur in the gastrulation period.
The primitive streak is the structure that develops during the early stages of the gastrulation. As the embryo becomes asymmetric., the cells moves from their initial position and leads to the formation of primitive streak in the gastrulation phase.
An example of a system would be the circulatory system helps circulate blood carrying nutrients to organs and waste material away from organs. It includes the organs - heart, blood vessels and lungs.
They would be biased towards the patient and the patient wouldn't get the best care or get to much attention and the nurse would be too distracted for others.
