When the two mutations are on the same chromosome, the arrangement is called the:

a. coupling configuration

b. cis configuration

c. repulsion configuration

d. coupling cofiguration and cis configuration

e. cis configuration and repulsion configuration

d. coupling configuration and cis configuration

Explanation:

Coupling configuration and cis configuration refers to the same type of arrangement of wild type and mutant alleles of the genes. Genes are present in pairs on homologous chromosomes. When two mutant alleles are present on the same homologous chromosome of the pair while the respective wild type alleles are present on the other chromosome of the homologous pair, it is called coupling or cis configuration. Example: a+ and b+ on the same chromosome and mutant a and b on the other chromosome of the homologous pair.

On the other hand, when two mutant alleles are across from each other, that is, they are present on the different chromosomes of a homologous pair, the arrangement is called trans or repulsion configuration.