AP Environmental Science

Answer: D - Rapid growth occurs in nonhuman populations during the log phase.

Key Takeaway: It is generally believed that nonhuman populations will continue to grow exponentially when the population size is low and most of the resources in the ecosystem are unutilized. But as resources become lower, the growth rate will slow. When this population reaches its carrying capacity, the population will stop growing and become constant. This is called logistical growth. Logistical growth is characterized by three phases: lag phase (the phase in which the population starts growing), the log phase (during which the population grows rapidly), and the stable phase (when the population growth slows and approaches its carrying capacity)