Final answer:
At carrying capacity, resource consumption equals resource replenishment, birth rate equals death rate, and the population growth rate is near zero, all of which maintain population sustainability.
Step-by-step explanation:
When a population reaches its carrying capacity, several conditions are typically observed. First, the rate at which resources are consumed by the population becomes equal to the rate at which they are replenished, creating a balance. Additionally, since the resources are limited, the population stops growing because the birth rate and death rate become nearly equal, leading to a situation where there is no significant increase or decrease in population size over time. Consequently, the population growth rate is at or near zero since new births and deaths are in balance. These conditions are essential for the population to be sustainable without depleting the resources available within its environment.