A genetic cross involving two traits is called a

• A. Allele
• B. Dihybrid
• C. Codon
• D. Chromosome

Answer: (B)

Studying inheritance for two traits at once is a dihybrid cross. The “di-” prefix means two, and a hybrid cross means you’re crossing individuals to see how two different genes combine and segregate in the offspring. This type of cross helps illustrate independent assortment when the genes are located on different chromosomes or far apart on the same chromosome. If both traits are tracked in heterozygous parents, you often get a characteristic phenotypic pattern, such as the 9:3:3:1 ratio, showing how the two genes segregate together in new combinations.

An allele is simply a variant form of a single gene, not a crossing of two traits. A codon is a set of three nucleotides in mRNA that codes for an amino acid, not a cross. A chromosome is the structure that carries many genes, not a cross between two traits.