What term describes the process by which the genetic makeup of a population changes over time?

• A. Evolution
• B. Artificial Selection
• C. Variation of Traits
• D. Chromosome

Answer: (A)

Changes in a population's genetic makeup over generations are called evolution. This means the frequencies of different alleles—the versions of genes—shift over time, often because certain traits help individuals survive and reproduce more than others. Natural selection is one way evolution happens, but other processes like genetic drift, mutations, gene flow, and nonrandom mating also contribute. Artificial selection is when humans steer trait changes, which is related in outcome but not the natural process. Variation of traits simply describes differences among individuals, not the ongoing change itself. A chromosome is just a structure that carries DNA, not the process of population change. So evolution is the term that describes how genetic makeup changes over time.