Final answer:
The leveling off of a population growth curve when the carrying capacity of the environment is reached describes Logistic growth, which is represented by an S-shaped curve in contrast to the J-shaped curve of exponential growth.
Step-by-step explanation:
Logistic growth is characterized by a population expansion that initially resembles exponential growth; however, as resources become limited, the rate of growth decreases and eventually levels off, reaching a plateau at the carrying capacity. The carrying capacity is the maximum population size that an environment can sustain.
Unlike exponential growth, which is represented by a J-shaped curve indicating a constant rate of increase, logistic growth produces an S-shaped curve. This more realistic model reflects the three phases of logistic growth: the initial exponential increase, the reduced growth as competition for resources intensifies, and finally, the leveling off at the carrying capacity where the population stabilizes.