Question

question 5 of 20 : select the best answer for the question. 5. when the population of organisms in an environment nears the carrying capacity, what inevitably happens to the population growth rate? a. continues growing logistically b. continues growing exponentially c. changes from exponential to logistic growth d. changes from logistic to exponential growth mark for review (will be highlighted on the review page) << previous question next question >>

Explanation:

To solve this, we recall population growth concepts:

• Exponential growth occurs when resources are unlimited (no carrying capacity constraints, growth rate \( r \) is constant, curve is J - shaped).
• Logistic growth occurs when resources become limited as population nears carrying capacity (\( K \)), introducing a limiting factor. The growth rate slows, and the curve is S - shaped.

When a population nears carrying capacity, resource limitations (like food, space) come into play. Initially, if resources were unlimited, growth was exponential. As carrying capacity is approached, growth transitions to logistic (since growth rate is now limited by \( K \)).

Let's analyze the options:

• Option A: “Continues growing logistically” — Logistic growth starts when limitations are present. But the transition (from exponential to logistic) happens as carrying capacity is neared, not that it “continues” logistic (implying it was already logistic, which isn't the case initially with unlimited resources). Eliminate.
• Option B: “Continues growing exponentially” — Exponential growth requires unlimited resources. Near carrying capacity, resources are limited, so exponential growth can’t continue. Eliminate.
• Option C: “Changes from exponential to logistic growth” — This matches the concept: initial exponential (unlimited resources) shifts to logistic (limited resources as \( K \) is neared). Correct.
• Option D: “Changes from logistic to exponential growth” — Logistic growth is because of carrying capacity limits; reverting to exponential would require resources to become unlimited again, which doesn’t happen as population nears \( K \). Eliminate.

Answer:

C. Changes from exponential to logistic growth