A cross between individuals that differ in a single trait is called what?

• A. Dihybrid cross
• B. Monohybrid cross
• C. Hybrid cross
• D. Backcross

Answer: (B)

Tracking inheritance of a single gene across generations is called a monohybrid cross. It focuses on one trait and the two alleles that determine it, showing how they segregate and recombine according to Mendel’s rules. When two individuals differ in only one trait, crossing them illustrates how a single gene with two alleles is inherited, often producing a 3:1 phenotypic ratio in the next generation if there is a simple dominant-recessive relationship, and a 1:2:1 genotype ratio among the offspring. The other terms describe crosses involving more than one trait (dihybrid), crosses that don’t specify a single trait (hybrid in a general sense), or crosses back to a parental type (backcross).