What is the Difference Between Test Cross and Backcross?

🆚 Go to Comparative Table 🆚

The main difference between a test cross and a backcross lies in their purpose and the types of individuals involved in the cross:

Test Cross:

  1. It is a cross between the F1 individual and the recessive parent.
  2. It is used to determine the genotype of F1 individuals, whether homozygous or heterozygous.
  3. All test crosses are considered backcrosses.

Backcross:

  1. It is a cross between the F1 individual and either of the two parents.
  2. It is used to improve a variety or breed by making a number of backcrosses.
  3. All backcrosses are not considered test crosses.

In a test cross, the dominant phenotype is crossed with the homozygous recessive phenotype (parent) to determine the genotype of the F1 individual. On the other hand, a backcross involves breeding the F1 generation with one of its parent plants to improve a variety or breed.

Comparative Table: Test Cross vs Backcross

Here is a table comparing the differences between a test cross and a backcross:

Characteristic Test Cross Back Cross
Definition A cross between the F1 individual and the recessive parent to determine the genotype of the F1 individual (homozygous or heterozygous). A cross between the F1 individual and either of the two parents to improve a variety or breed by making a number of backcrosses.
F1 Hybrid Crossing Crossed with a recessive genotype. Crossed with either a homozygous dominant or heterozygous genotypes.
All Test Crosses All test crosses are considered backcrosses. A backcross can be considered a test cross if the parent is recessive.
Role of Action Used to determine the genotype of the F1 individual, whether homozygous or heterozygous. Used to improve a variety or breed by making a number of backcrosses.

In summary, a test cross is used to determine the genotype of an F1 individual, while a backcross is used to improve a variety or breed by making multiple crosses with one of the parental lines. All test crosses are considered backcrosses, but not all backcrosses are test crosses.