Advanced Placement (AP) Biology Practice Exam

What does the law of Independent Assortment explain?

1. Alleles of non-linked genes separate independently during gamete formation

2. Only linked alleles segregate away from one another

3. All genes assort independently regardless of linkage

4. Multigenic traits assort uniformly in gametes

The correct answer is: Alleles of non-linked genes separate independently during gamete formation

The law of Independent Assortment, originally formulated by Gregor Mendel, specifically refers to how alleles of non-linked genes segregate independently from one another during the formation of gametes. This means that the distribution of alleles for one gene does not affect the distribution of alleles for another gene that is not linked on the same chromosome. When gametes are formed, the segregation of alleles takes place in a way that the combinations of alleles for different traits are varied. This leads to genetic variation, as offspring can inherit different combinations of traits from their parents. The underlying principle is that genes located on different chromosomes, or far apart on the same chromosome, will assort into gametes independently of one another during meiosis. This law is crucial for understanding inheritance patterns and predicting the genotypes of future generations. In contrast, the other options misrepresent the concept. For example, linked alleles refer to genes located close to each other on the same chromosome, which do not assort independently due to genetic linkage. While the law states that non-linked genes assort independently, it does not necessarily imply that all genes, regardless of linkage, will assort independently. Additionally, multigenic traits, which involve multiple genes influencing a single trait,