Two crosses between the same pair of genotypes or phenotypes in which the sources of the gametes are reversed in one cross, is known as:

Explanation

A test cross is used to determine the genotype of an individual with a dominant phenotype by crossing it with a known homozygous recessive individual. A reciprocal cross involves performing two crosses between the same genotypes or phenotypes but reversing the sources of gametes in one of the crosses. This is often used to test for sex-linked inheritance or parental effects. A dihybrid cross is a genetic cross involving two individuals heterozygous for two different genes to study the inheritance of both traits simultaneously. "Reverse cross" is not a recognized term in genetics. In the context of your question, the correct answer is "b. Reciprocal cross." It's an important tool in genetics to explore the effects of parental contributions in different ways and is not related to the other options provided.