Which law states that genes separate independently of one another during meiosis?

• A. Law of Independent Assortment
• B. Law of Segregation
• C. Law of Dominance
• D. Law of Crossing Over

Answer: (A)

The main idea here is how genes are sorted into gametes during meiosis. The Law of Independent Assortment describes how different genes (or the different alleles they carry) separate independently of one another as gametes form. During meiosis I, homologous chromosome pairs align and then segregate into gametes in a random orientation. Because each pair’s orientation is independent of the others, the combination of maternal and paternal alleles that end up in a given gamete is random, producing many possible genetic combinations.

This explains why traits controlled by genes on different chromosomes (or far apart on the same chromosome) tend to assort independently, contributing to genetic variation in offspring. If genes are tightly linked on the same chromosome, they may not assort independently unless crossing over occurs between them, which is a separate mechanism that can shuffle alleles.

The other laws describe different ideas: the Law of Segregation says that the two alleles of a single gene separate into gametes, the Law of Dominance concerns how dominant and recessive alleles are expressed, and crossing over is the physical exchange of chromosome segments during prophase I that creates new allele combinations but isn’t itself the rule about how genes assort.