The growth pattern where the rate of population growth slows and levels off after an initial exponential increase is called ...

The growth pattern where the rate of population growth slows and levels off after an initial exponential increase is called ...

• A. Logistic growth
• B. Exponential growth
• C. Pioneer species
• D. Population density

Answer: (A)

Growth that starts fast but then slows and levels off happens because resources become limiting as the population grows. When a population is small and resources are abundant, it can increase rapidly, but as numbers rise, competition for food, space, and other needs increases. This raises death rates or lowers birth rates, so the overall growth rate declines and the population approaches a stable size called carrying capacity—the maximum number the environment can sustain long term. Once near that limit, births roughly balance deaths and the curve flattens, producing the characteristic S-shaped, or logistic, growth pattern. In contrast, exponential growth would keep accelerating without leveling off; a pioneer species describes early colonizers rather than a growth pattern; population density is a measure, not a growth pattern.

Growth that starts fast but then slows and levels off happens because resources become limiting as the population grows. When a population is small and resources are abundant, it can increase rapidly, but as numbers rise, competition for food, space, and other needs increases. This raises death rates or lowers birth rates, so the overall growth rate declines and the population approaches a stable size called carrying capacity—the maximum number the environment can sustain long term. Once near that limit, births roughly balance deaths and the curve flattens, producing the characteristic S-shaped, or logistic, growth pattern. In contrast, exponential growth would keep accelerating without leveling off; a pioneer species describes early colonizers rather than a growth pattern; population density is a measure, not a growth pattern.