Final answer:
The statement is true; a population with a growth rate (λ) of 1 signifies a stable-age distribution, where birth and death rates are balanced and the population size remains constant.
Step-by-step explanation:
The statement that a population in which λ equals one has reached a stable-age distribution is true. When λ, or the population growth rate, equals 1, it indicates that the birth rate and death rate are balanced, resulting in no overall change in the population size. This equilibirum implies a stable-age distribution. Populations can show different types of growth patterns: exponential growth, where the population size doubles over time, or logistic growth, where the growth rate decreases as the population size approaches the carrying capacity of the environment. In a logistic growth scenario, the population eventually stabilizes at the carrying capacity, and the age structure of the population becomes stable, reflecting the steady state where birth rates and death rates are in equilibrium.