Other sites let you use the Google Authenticator app to generate the six-digit number. The app generates a different six-digit number for each connected site, and these numbers change every 30 seconds. With the app, you don't have to wait a few seconds to receive a text message.
Factors that cause population growth include increased food production, improved health care services, immigration and high birth rate. These factors have led to overpopulation, which has more negative effects than positive impacts. Keep Learning.
There are several types of density-dependent factors, but they all have two things in common: they influence the rates of births and deaths, and the effect increases as population size increases. When the density of a population is low (few individuals in a given area), resources are not limiting. There are plenty of resources for everyone. More individuals can give birth, and fewer individuals will die.