Biology 30 – Populations Practice Test

Carrying capacity is the maximum number of individuals an environment can sustain indefinitely given the available resources, space, and waste removal. As a population grows toward that limit, resources become scarcer and competition intensifies, causing the per‑capita growth rate to decline. Because births minus deaths slow down with increasing density, the population’s growth approaches zero and the size tends to stabilize near the carrying capacity. If the population overshoots, resource depletion can trigger higher mortality or reduced reproduction, bringing numbers back down toward the limit. Remember that carrying capacity can shift with changes in resources, climate, or technology, so long‑term population size generally centers around this upper bound, even though it may fluctuate around it.