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.