Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: 45.3 Environmental Limits to Population Growth Populations with unlimited resources grow exponentially, with an accelerating growth rate. When resources become limiting, populations follow a logistic growth curve. The population of a species will level off at the carrying capacity of its environment. Answer: carrying capacity
A:
While populations with unlimited resources grow exponentially, the population of a species will level off when what limit of its environment is reached?