Back Cross and Test Cross

A test cross is defined as a genetic cross between an individual showing a dominant phenotype with unknown genotype and a homozygous recessive individual to determine the genotype of the dominant individual.

A back cross is defined as a genetic cross between an F₁ hybrid and either of its parental forms (dominant or recessive) to study inheritance of traits.

• Back cross is the cross between the F₁ hybrid and either of its parents (dominant or recessive).
• A test cross is a special type of backcross where the F₁ hybrid is crossed with a homozygous recessive parent.
• Backcross is used to obtain desirable traits and may produce all dominant offspring when crossed with a dominant parent.
• A test cross is used to determine the genotype (homozygous or heterozygous) of an organism showing a dominant trait.
• In a test cross, a 1:1 ratio of dominant and recessive traits indicates a heterozygous condition.
• If all offspring show dominant traits in a test cross, the parent is homozygous dominant.
• Test cross is simple, reliable, and widely used in plant breeding and crop improvement.