A cross between individuals that involves one pair of contrasting traits is known as what?

A cross between individuals that involves one pair of contrasting traits is known as what?

• A. Dihybrid cross
• B. True-breeding cross
• C. Monohybrid cross
• D. Backcross

Answer: (C)

The main idea is how a single gene with two contrasting alleles is inherited when two individuals with different versions of that trait mate. This is a monohybrid cross. It shows how the two alleles for that one trait segregate into gametes and then recombine at fertilization, often producing offspring that display a dominant phenotype most of the time and a recessive phenotype in about a 3:1 ratio when both parents are heterozygous. For example, crossing plants that differ only in height with alleles T and t (Tt × Tt) yields mostly tall plants but some short ones, illustrating dominant and recessive relationships. The other terms describe crosses involving more than one trait, homozygous parents, or crosses back to a parent, which don’t match the idea of a single-trait cross.

The main idea is how a single gene with two contrasting alleles is inherited when two individuals with different versions of that trait mate. This is a monohybrid cross. It shows how the two alleles for that one trait segregate into gametes and then recombine at fertilization, often producing offspring that display a dominant phenotype most of the time and a recessive phenotype in about a 3:1 ratio when both parents are heterozygous. For example, crossing plants that differ only in height with alleles T and t (Tt × Tt) yields mostly tall plants but some short ones, illustrating dominant and recessive relationships. The other terms describe crosses involving more than one trait, homozygous parents, or crosses back to a parent, which don’t match the idea of a single-trait cross.