Answer:
It is possible to identify the function of a gene by site-specific targeted mutagenesis (i.e., by using a reverse genetics approach).
Explanation:
Targeted mutagenesis is an approach widely used in molecular biology in order to determine the functions of endogenous genes. Targeted mutagenesis is a type of genetic technique known as reverse genetics since it is a technology that enables to identify the function of a gene by modifying its product (i.e., its corresponding messenger RNA), thereby synthesizing non-functional proteins.
Moreover, it is also possible to identify the function of a gene by altering its expression, for example, by using small interfering RNAs (siRNAs) that inhibit protein translation through RNA interference (RNAi) mechanisms.