What is the term for the basic units of heredity that differ among individuals?

• A. Genes
• B. Alleles
• C. Loci
• D. Genomes

Answer: (B)

Differences among individuals come from different versions of a gene, called alleles. A gene is a basic unit of heredity, but the variation that makes people different arises because there are multiple alleles for many genes. Loci are the exact locations on a chromosome where those genes sit, and a genome is the entire set of an organism’s genetic material. In forensic genetics, profiling relies on detecting specific alleles at multiple loci to distinguish individuals.