Kaplan Nursing Entrance Practice Exam

Which concept helps understand how certain traits may disappear from a population?

1. Natural selection

2. Genetic drift

3. Allele frequency

4. Gene flow

The correct answer is: Allele frequency

To understand how certain traits may disappear from a population, it is important to consider allele frequency. Allele frequency refers to how often a particular allele appears within a population's gene pool. If certain alleles that correspond to specific traits become less common—perhaps due to factors like environmental changes, disease, or competition—the traits associated with those alleles can diminish or vanish from that population over time. For example, if a particular allele that results in a beneficial trait becomes rare, the individuals exhibiting that trait may have reduced reproductive success, further decreasing the allele's frequency. This concept highlights the dynamic nature of gene distribution in a population, demonstrating that changes in allele frequencies can lead to observable shifts in the traits present. This underscores the role of genetic principles in evolution and population changes. Other concepts such as natural selection, genetic drift, and gene flow address different mechanisms that can influence populations, but the direct impact on trait disappearance is most clearly articulated through the lens of allele frequency. Natural selection focuses on how certain traits confer survival advantages, genetic drift pertains to random changes in allele frequencies, and gene flow involves the transfer of alleles between populations. However, the concept of allele frequency more directly encapsulates the mechanisms through which traits can fade from a population