Answer:
-Reporter gene.
Explanation:
A reporter gene can be defined as a gene, which is used as an indicator to check uptake or expression of gene by a cell or organism. It is attached to a regulatory sequence of a different gene of interest in cell culture, bacteria, plants, or animals by the researchers and used to confer its expression in that organism or cell.
Gene for GFP (green fluorescent protein) is an example of reporter gene, due to which cells that express gene of interest emit green color under blue light.
As in given experiment, target gene (gene for rhodopsin) is attached with gene for GFP, it represents an example of reporter gene.
Thus, the correct answer is 'reporter gene.'
