Which graph best illustrates a population that was growing and has reached its carrying capacity?

• A. A J-shaped curve that continues to rise exponentially
• B. A sigmoidal (S-shaped) curve that levels off at the top
• C. A straight, upward-sloping line with no plateau
• D. A horizontal line showing no change in population size

Answer: (B)

Verified step by step guidance

1. Understand the concept of carrying capacity: Carrying capacity refers to the maximum population size that an environment can sustain indefinitely, given the available resources such as food, water, and shelter.
2. Recognize the type of population growth: Populations initially grow exponentially when resources are abundant, but as resources become limited, growth slows and stabilizes at the carrying capacity.
3. Identify the graph that represents this pattern: A sigmoidal (S-shaped) curve best illustrates this scenario. The curve starts with exponential growth, then slows as the population approaches the carrying capacity, and finally levels off at the top.
4. Compare the other graph options: A J-shaped curve represents unchecked exponential growth without resource limitations, which does not account for carrying capacity. A straight, upward-sloping line implies constant growth without slowing, and a horizontal line indicates no population growth at all.
5. Conclude that the sigmoidal (S-shaped) curve is the correct answer because it accurately represents a population growing and stabilizing at its carrying capacity.