In yeast, you have sequenced a piece of wild-type DNA and it clearly contains a gene, but you do not know what gene it is. Therefore, to investigate further, you would like to find out its mutant phenotype. How would you use the cloned wild-type gene to do so?

Introduce a mutation into the gene

Explanation:

In order to understand what is the purpose of the gene (protein) is there are a couple of options that can be take to identify it;s purpose.

One way to do this is to introduce a mutation into the wild type gene clone by site directed mutagenesis or by gene disruption. After the cloned gene is altered it can be re-introduced back into the wild-type  yeast. The yeast is then allowed to multiply and the effect that the mutation has on the yeas can be observed.

Creating Mutant phenotype,both allele for that quality ought to be change (with respect to prevailing phenotype ,regardless of whether one duplicate is normal,phenotype will be normal).If that quality can't play out its capacity ,at that point it's lack will be found in freak phenotype, and we look at wild kind one and freak , capacity of that quality can be known, as this capacity will discover in ordinary wild sort one and missing in freak phenotype. Steps-take to cloning vector, one contain ordinary wild sort quality and second contain mutant gene. Addition them independently in various host cell and see the outcome.