Final answer:
Skin color as observed by a nurse within a diverse population signifies race, which is a social construct based on physical attributes that differ around the world.
Step-by-step explanation:
A nurse working with a diverse population recognizes that skin color of individuals is an example of race. The term 'race' refers to superficial physical differences considered significant within a society. Contrarily, ethnicity describes shared culture and experiences. The skin color variation, which ranges from pinkish beige to dark brown, is an evolutionary adaptation to different levels of sunlight across the globe. Therefore, race is often perceived in terms of physical attributes like skin color, which can be an imprecise social construct rather than a defined biological category.