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.
AAG Center for Global Geography Education. Population Growth in California. Looking at the larger state scale, California is the most populous state in the United States with an estimated 36.8 million residents in 2008 (US Census Bureau 2008a). Its rate of population growth was explosive from after World War II to the first years of the 21st century. Although the rate of growth has slowed recently, it was still among the highest in the U.S. between 2000 and 2005 (Figure 3).