What term describes a number that explains how fast a given population grows, positive or negative, and is calculated using immigration and emigration fluctuations?

• A. Population growth rate
• B. Birth rate
• C. Carrying capacity
• D. Death rate

Answer: (A)

The main idea is the net rate at which a population changes over time, incorporating all sources of change. This term, population growth rate, measures how fast a population is increasing or decreasing per unit time, and it includes births and deaths as well as movements of individuals into and out of the population through immigration and emigration. If there are more individuals entering than leaving and more births than deaths, the growth rate is positive; if the opposite happens, it’s negative. This distinguishes it from birth rate (which only counts births), death rate (which only counts deaths), or carrying capacity (the maximum population the environment can support, not a rate). Thus the described concept is population growth rate.