Which of the following is NOT a key component of a population?

In the context of population studies, the key components typically include size, distribution, and density. Size refers to the total number of individuals within a population, distribution describes how individuals are spread out across a given area, and density is a measure of how many individuals exist in a specific unit of area or volume.

Culture, while an important sociological aspect that influences social behavior and interactions within a population, is not a key demographic component used to describe the basic characteristics of a population. It relates more to the shared beliefs, norms, and practices of a group rather than the quantitative aspects that define a population's structure. Thus, selecting culture as the answer correctly identifies it as not being essential in the demographic framework for analyzing populations.