A molecular geneticist is studying a gene region where 30% of individuals in a population carry a risk allele. In a sample of 800 individuals, 15% are homozygous for the allele, and 40% are heterozygous. Assuming Hardy-Weinberg equilibrium, how many individuals are expected to be non-carriers?

Thu, 16 Apr 2026 06:50:14 +0000

A molecular geneticist is studying a gene region where 30% of individuals in a population carry a risk allele. In a sample of 800 people, 15% are homozygous for the allele, and 40% are heterozygous. Assuming Hardy-Weinberg equilibrium, this results in a clear distribution of genetic variants. The remaining individuals are non-carriers—those with no or minimal risk from the genotype. Understanding allele frequencies and genotype patterns helps translate genetic research into meaningful public health insights. With growing interest in personal genetics and precision medicine, this kind of data sheds light on inherited disease risks at the population level. Why is this topic gaining attention in the US? Increasing access to at-home genetic testing and rising awareness of lifestyle and genetic factors in health outcomes have sparked broader public curiosity. Consumers seek clear, science-backed answers about genetic predispositions, especially for conditions with complex inheritance patterns. As they process how genes interact with environment and health, questions about allele distribution and genetic risk become more relevant beyond clinical settings. To understand how many individuals are non-carriers, researchers rely on the Hardy-Weinberg principle—a foundational model in population genetics. This principle predicts expected genotype frequencies from allele frequencies under ideal conditions: no mutation, random mating, no selection, large population, and no migration. When genetic data aligns with these assumptions, scientists can estimate how many individuals carry risk alleles, homozygous or heterozygous, and how many remain unaffected—non-carriers—by calculation. In detail: