Advanced Placement (AP) Biology Practice Exam

What does the term "wild type" refer to in genetics?

1. An individual with a rare genetic mutation

2. An individual displaying the most common phenotype in nature

3. A genetically engineered organism

4. A phenotype resulting from environmental changes

The correct answer is: An individual displaying the most common phenotype in nature

The term "wild type" refers specifically to an individual exhibiting the most common phenotype found in a natural population. This phenotype serves as a standard or reference for comparison to other variants, often associated with specific traits governed by genetics. In the context of genetics, "wild type" usually describes alleles or phenotypes that are prevalent within a natural environment, representing the typical form without any mutations. This understanding is essential as it helps clarify the concept of genetic variation. For example, when researchers study mutations or genetic diversity, they often reference the wild type to assess how much a specific mutation deviates from the common phenotype. The designation underscores the importance of natural selection and adaptability, as wild type organisms are generally well-suited for their environments. In contrast, the other options describe concepts that do not align with the definition of "wild type." For example, rare genetic mutations and genetically engineered organisms represent deviations from the wild type rather than the typical form. Similarly, phenotypes resulting from environmental changes pertain more to phenotypic plasticity, where an organism's traits shift due to non-genetic factors, further distancing them from the idea of a "wild type." Thus, the definition grounded in the most common phenotype in nature provides a clear framework for understanding