A cross between two individuals, concentrating on two definable traits is called?

• A. Monohybrid cross
• B. Dihybrid cross
• C. Test cross
• D. Back cross

Answer: (B)

Studying two traits at once is a dihybrid cross. This type of cross tracks two different gene loci to show how their alleles segregate and, when unlinked, assort independently under Mendel’s law. For example, crossing individuals heterozygous for both traits (AaBb x AaBb) typically produces offspring in a 9:3:3:1 phenotypic ratio, reflecting the four possible combinations of the two traits. This is different from a monohybrid cross, which follows just one trait and often yields a 3:1 ratio. A test cross involves crossing with a homozygous recessive to reveal the unknown genotype, while a back cross pairs an offspring with a parent or a genetically similar individual.