5. Sodium-potassium pump: Protein mechanism found along the neuron membrane which transports 3 Na+ ions outside of the cell while also drawing 2 K+ ions into the cell; this is an active transport mechanism (requires energy (ATP) to function). 6.
What Is the Population Density of the United States? The population density of the United States is approximately 87.4 people per square mile, according to the 2010 U.S. Census. What Is the Most Densely Populated Continent? Perhaps not surprisingly, the most densely populated continent is Asia. Here are the population densities of the continents: 1  North America - 32 people per square mile. 2  South America - 73 people per square mile. 3  Europe - 134 people per square mile. 4  Asia - 203 people per square mile. 5  Africa - 65 people per square mile. 6  Australia - 6.4 people per square mile.
About 1 in every 38 people living in the United States resides in New York City. New York has the highest population density of any major city in the United States, with over 27,000 people per square mile. Over 3 million of New York Cityâs residents are foreign-born; over one-quarter arrived in 2000 or later. Nearly 2 million New Yorkers are under the age of 18.