Final answer:
A reporter gene is an experimentally engineered regulatory DNA sequence that is fused to a gene encoding an easily observable protein. This approach is useful for tracking the expression patterns of genes of unknown function and provides valuable information about gene function and localization.
Step-by-step explanation:
A reporter gene is an experimentally engineered regulatory DNA sequence from a gene of interest that has been fused to a gene that encodes a protein that is easily observed experimentally. This approach is useful because it allows researchers to track the expression patterns of genes of unknown function. By attaching a reporter gene to a gene of interest, they can easily monitor its location and activity in an organism. This provides valuable information about the gene's function and localization.