Final answer:
The newborn is demonstrating the Moro reflex when the nurse accidentally bumps into the bassinet.
Step-by-step explanation:
The reflex demonstrated by the newborn in this scenario is the Moro reflex. The Moro reflex is a protective reflex in infants that is triggered by a sudden movement or loud noise. When the nurse accidentally bumps into the newborn's bassinet, the newborn jumps and pulls the extremities into the trunk as a natural response to the startle. This reflex helps the newborn in survival by allowing them to quickly respond and protect themselves from potential danger.