Question

quiz how populations grow
the population of adult frogs in a wetlands ecosystem has increased to 1000 individuals, which is its carrying capacity. the frogs eat flies and other small animals, and they are prey for raccoons, snakes, and a variety of large birds.
which most likely would happen if an additional 200 adult frogs immigrated to the ecosystem?
a. the carrying capacity for frogs in the ecosystem would increase by 200 frogs.
b. the carrying capacity for frog predators in the ecosystem would increase by 200 individuals.
c. the frog population would experience a pattern of exponential growth.
d. about 200 adult frogs would die because of lack of resources, or by predation.

Explanation:

• Option A: Carrying capacity is determined by ecosystem resources (food, space, etc.), not by immigration of frogs. So it won't increase just because 200 frogs immigrate.
• Option B: Carrying capacity for predators depends on their own resources and the frog population as a food source, but a sudden 200 - frog immigration won't directly increase predator carrying capacity by 200.
• Option C: Exponential growth occurs when resources are unlimited, but the ecosystem already reached its carrying capacity for frogs, so resources are limited. Thus, exponential growth won't happen.
• Option D: Since the ecosystem's carrying capacity for frogs is 1000, adding 200 more frogs (total 1200) exceeds the capacity. Due to limited resources (food, space) and increased predation (more prey for predators), about 200 frogs are likely to die to bring the population back towards the carrying capacity.

Answer:

D. About 200 adult frogs would die because of lack of resources, or by predation.