What process involves extracting a fertilized egg, inserting desired genes, and implanting it back into a host?

The process described involves the extraction of a fertilized egg, introducing specific genes into it, and subsequently implanting this genetically modified egg back into a host organism. This technique is generally recognized as microinjection, where DNA or RNA can be directly introduced into the nucleus of a cell, such as a fertilized egg.

Microinjection allows researchers to precisely manipulate genetic material at the single-cell stage, which is crucial for producing genetically modified organisms (GMOs). Once the desired genes are inserted, the fertilized egg can develop into a new organism with the introduced genetic modifications.

In contrast, gene editing typically involves altering existing genes within an organism, rather than directly inserting new genes into a fertilized egg. Cloning refers to creating genetically identical copies of an organism, while CRISPR technology is a method of gene editing that uses a specific system to target and modify genes but does not directly involve the implantation of a fertilized egg. Therefore, microinjection is the most accurate answer in this context.