The technology that uses genetic engineering to replace one or more genes in an organism is called gene editing.

Here's a breakdown:

* Gene editing: This is a broad term encompassing various techniques that allow scientists to precisely alter an organism's DNA sequence. This can involve replacing, inserting, or deleting specific genes.

* CRISPR-Cas9: This is a revolutionary gene editing technology that has gained immense popularity in recent years due to its precision and ease of use. It acts like a pair of molecular scissors that can target and cut specific DNA sequences, enabling the insertion or deletion of genes or the correction of mutations.

There are other gene editing techniques besides CRISPR-Cas9, but it's currently the most widely used and promising.

Gene editing has vast potential applications in:

* Medicine: Developing therapies for genetic diseases, creating disease-resistant crops, and personalized medicine.

* Agriculture: Enhancing crop yields, creating pest-resistant plants, and improving nutritional content.

* Research: Studying the functions of genes and developing new research models.

However, there are also ethical concerns about the use of gene editing, particularly in humans. This is why strict regulations and ethical considerations are crucial for ensuring its responsible application.