Question

Molecular Cell Biology

What question is a complementation test (analysis) designed to answer? How does it answer the question (include expected results)?

Answer 1

Complimentation test is perform to determining whether two mutations associated with a specific phenotype represent two different forms of the same gene or are variations of two different genes.

The complimentation test is relevant for recessive traits ( normally not present in the phenotype due to effect of dominant allele).  

When two parent organisms each carry two mutant genes in a homozygous recessive state, causing the recessive trait to be expressed, the complimentation test can determine whether the recessive trait will be expressed in the next generation.  

When two mutations occur in different genes, they are said to be complimentary, because the heterozygote condition rescues the function otherwise lost in the homozygous recessive state.